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. This example and kernel fix has come from Amir Goldstein. I am just putting a test for it to make sure its not broken down the line. Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx> --- tests/overlay/057 | 97 ++++++++++++++++++++++++++++++++++++++++++++++++++ tests/overlay/057.out | 2 + tests/overlay/group | 1 3 files changed, 100 insertions(+) Index: xfstests-dev/tests/overlay/057 =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ xfstests-dev/tests/overlay/057 2018-03-12 13:28:02.274818432 -0400 @@ -0,0 +1,97 @@ +#! /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@xxxxxxxxxx> +# +# 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 $seqres.full + +# real QA test starts here +_supported_fs overlay +_supported_os Linux +_require_scratch_nocheck +_require_scratch_overlay_features redirect_dir + +# remove all files from previous tests +_scratch_mkfs + +# Create test directories +lowerdir=$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 + +make_test_dirs() +{ + rm -rf $lowerdir $lowerdir2 $upperdir $workdir $workdir2 + mkdir -p $lowerdir $lowerdir2 $upperdir $workdir $workdir2 +} + +make_test_dirs +mkdir -p $lowerdir/origin +touch $lowerdir/origin/foo +_overlay_scratch_mount_dirs $lowerdir $lowerdir2 $workdir2 +mkdir $SCRATCH_MNT/pure +mv $SCRATCH_MNT/origin $SCRATCH_MNT/pure/redirect +$UMOUNT_PROG $SCRATCH_MNT +_overlay_scratch_mount_dirs $lowerdir2:$lowerdir $upperdir $workdir +mv $SCRATCH_MNT/pure/redirect $SCRATCH_MNT/redirect +$UMOUNT_PROG $SCRATCH_MNT +_overlay_scratch_mount_dirs $lowerdir2:$lowerdir $upperdir $workdir +ls $SCRATCH_MNT/redirect/ + +# success, all done +status=0 +exit Index: xfstests-dev/tests/overlay/group =================================================================== --- xfstests-dev.orig/tests/overlay/group 2018-02-28 15:27:29.981693615 -0500 +++ xfstests-dev/tests/overlay/group 2018-03-12 09:31:45.692818432 -0400 @@ -59,3 +59,4 @@ 054 auto quick copyup redirect exportfs 055 auto quick copyup redirect exportfs nonsamefs 056 auto quick fsck +057 auto quick redirect Index: xfstests-dev/tests/overlay/057.out =================================================================== --- /dev/null 1970-01-01 00:00:00.000000000 +0000 +++ xfstests-dev/tests/overlay/057.out 2018-03-12 13:09:42.061818432 -0400 @@ -0,0 +1,2 @@ +QA output created by 057 +foo -- To unsubscribe from this list: send the line "unsubscribe linux-unionfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html