tests/overlay/057

#! /bin/bash
# FS QA Test No. 057
#
# Test absolute redirect is followed even if ancestor is opaque
#
# Typically, when following absolute redirect, if an opauqe dentry is
# found, lookup in further lower directories is stopped. But if a
# child dentry has another absolute redirect, then lookup in further
# lower layers should continue.
#
# Say, following is example setup.
# upper:  /redirect (redirect=/a/b/c)
# lower1: /a/[b]/c       ([b] is opaque) (c has absolute redirect=/a/b/d/)
# lower0: /a/b/d/foo
#
# "redirect" directory in upper should merge with lower1:/a/b/c/ and
# lower0:/a/b/d/, despite lower1:/a/b/ being opaque.
#
#-----------------------------------------------------------------------
# Copyright (C) 2018 Red Hat, Inc. All Rights Reserved.
# Author: Vivek Goyal <vgoyal@redhat.com>
#
# 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
_supported_fs overlay
_supported_os Linux
# We use non-default scratch underlying overlay dirs, we need to check
# them explicity after test.
_require_scratch_nocheck
_require_scratch_overlay_features redirect_dir

# remove all files from previous tests
_scratch_mkfs

# Create test directories
lowerdir=$OVL_BASE_SCRATCH_MNT/lower
lowerdir2=$OVL_BASE_SCRATCH_MNT/lower2
upperdir=$OVL_BASE_SCRATCH_MNT/upper
workdir=$OVL_BASE_SCRATCH_MNT/workdir
workdir2=$OVL_BASE_SCRATCH_MNT/workdir2

mkdir -p $lowerdir $lowerdir2 $upperdir $workdir $workdir2
mkdir -p $lowerdir/origin
touch $lowerdir/origin/foo
_overlay_scratch_mount_dirs $lowerdir $lowerdir2 $workdir2 -o redirect_dir=on

# Create opaque parent with absolute redirect child in middle layer
mkdir $SCRATCH_MNT/pure
mv $SCRATCH_MNT/origin $SCRATCH_MNT/pure/redirect
$UMOUNT_PROG $SCRATCH_MNT
_overlay_scratch_mount_dirs $lowerdir2:$lowerdir $upperdir $workdir -o redirect_dir=on
mv $SCRATCH_MNT/pure/redirect $SCRATCH_MNT/redirect
# List content of renamed merge dir before mount cycle
ls $SCRATCH_MNT/redirect/

# Verify that redirects are followed by listing content of renamed merge dir
# after mount cycle
$UMOUNT_PROG $SCRATCH_MNT
_overlay_scratch_mount_dirs $lowerdir2:$lowerdir $upperdir $workdir -o redirect_dir=on
ls $SCRATCH_MNT/redirect/

# check overlayfs
_overlay_check_scratch_dirs "$lowerdir2:$lowerdir" $upperdir $workdir -o redirect_dir=on

# success, all done
status=0
exit