Re: [PATCH] overlay: test basic whiteout

Xiong Zhou
2016-04-21T13:15:36Z

On Thu, Apr 21, 2016 at 08:57:32PM +0800, Eryu Guan wrote:
> On Thu, Apr 21, 2016 at 08:23:58PM +0800, Xiong Zhou wrote:
> > Overlayfs whiteout can be visible if underlying xfs was created
> > with ftype=0. Kernel commit
> > 45aebea (ovl: Ensure upper filesystem supports d_type)
> > prevents mounting overlayfs like this since v4.6-rc1. No harm to
> > keep this test as a sanity check.
>
> It turns out that the test harness won't even start if underlying XFS
> has no d_type support :)

Yes, so do other overlay test cases. Maybe we should check underlying
fs d_type support situation before running overlay cases, mark as
not run if need.

>
> mount: wrong fs type, bad option, bad superblock on /mnt/ovl/test,
> missing codepage or helper program, or other error
>
> In some cases useful info is found in syslog - try
> dmesg | tail or so.
> common/rc: retrying test device mount with external set
>
> But I still think it's good to have a whiteout sanity test.
>
> >
> > Signed-off-by: Xiong Zhou <xzhou@redhat.com>
> > ---
> > tests/overlay/003 | 78 +++++++++++++++++++++++++++++++++++++++++++++++++++
> > tests/overlay/003.out | 2 ++
> > tests/overlay/group | 1 +
> > 3 files changed, 81 insertions(+)
> > create mode 100755 tests/overlay/003
> > create mode 100644 tests/overlay/003.out
> >
> > diff --git a/tests/overlay/003 b/tests/overlay/003
> > new file mode 100755
> > index 0000000..2401075
> > --- /dev/null
> > +++ b/tests/overlay/003
> > @@ -0,0 +1,78 @@
> > +#! /bin/bash
> > +# FS QA Test 003
> > +#
> > +# Test overlayfs whiteout.
> > +#
> > +# Overlayfs whiteout can be visible if underlying xfs was created
> > +# with ftype=0. Kernel commit
> > +# 45aebea (ovl: Ensure upper filesystem supports d_type)
> > +# prevents mounting overlayfs like this since v4.6-rc1. No harm to
> > +# keep this test as a sanity check.
> > +#
> > +#-----------------------------------------------------------------------
> > +# Copyright (c) 2016 Red Hat Inc. All Rights Reserved.
> > +#
> > +# 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
> > +
> > +# remove previous $seqres.full before test
> > +rm -f $seqres.full
> > +
> > +# real QA test starts here
> > +
> > +# Modify as appropriate.
> > +_supported_fs overlay
> > +_supported_os Linux
> > +_require_scratch
> > +
> > +# Remove all files from previous tests
> > +_scratch_mkfs
> > +
> > +# Create test file in lower dir
> > +lowerdir=${SCRATCH_DEV}/${OVERLAY_LOWER_DIR}
> > +mkdir -p $lowerdir
> > +touch ${lowerdir}/test_file
>
> I think as a whiteout sanity test, more file types can be tested here,
> not only regular file, things like dir, hardlink, symlink, chardev,
> blkdev and named pipe should be tested as well.

Yes! I missed this. Great catch!

>
> > +
> > +_scratch_mount
> > +
> > +# whiteout file in overlay mount
> > +rm -f ${SCRATCH_MNT}/test_file
>
> Then all files can be removed here
> rm -rf ${SCRATCH_MNT}/*
>
> > +# it should not be listed
> > +ls -l ${SCRATCH_MNT}/test_file 2>&1 | awk -F: '{print $NF}'
>
> And no output expected here from ls
> ls ${SCRATCH_MNT}/
>
> > +
> > +_scratch_unmount
> > +
> > +# success, all done
> > +status=0
> > +exit
> > diff --git a/tests/overlay/003.out b/tests/overlay/003.out
> > new file mode 100644
> > index 0000000..83bafee
> > --- /dev/null
> > +++ b/tests/overlay/003.out
> > @@ -0,0 +1,2 @@
> > +QA output created by 003
> > + No such file or directory
>
> And probably we can change this to a simple "Silence is golden" and
> print it from the test.

en.. yes, this looks better.

>
> > diff --git a/tests/overlay/group b/tests/overlay/group
> > index 84d164e..f671c67 100644
> > --- a/tests/overlay/group
> > +++ b/tests/overlay/group
> > @@ -5,3 +5,4 @@
> > #
> > 001 auto quick copyup
> > 002 auto quick metadata
> > +003 auto quick
>
> Add a new "whiteout" group?

Good idea. Thanks very much for reviewing!

--
Xiong

>
> Thanks,
> Eryu