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apfstests/tests/overlay/049
T
Amir Goldstein 1fa396719e overlay: add a test for multiple redirects to the same lower dir
Multiple redirects to the same lower dir will falsely return the
same st_ino/st_dev for two different upper dirs and will cause
'diff' to falsely report that content of directories is the same
when it is not.

This test checks that overalyfs detects and fails lookup of a
multiply redirected dir.

The check for multiply redirected dir was implemented by kernel
commit titled "ovl: hash directory inodes for fsnotify".

Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Reviewed-by: Eryu Guan <eguan@redhat.com>
Signed-off-by: Eryu Guan <eguan@redhat.com>
2018-01-29 18:08:00 +08:00

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#! /bin/bash
# FS QA Test 049
#
# Test multiple redirects to the same lower dir.
#
# Multiple redirects to the same lower dir will falsely return the same
# st_ino/st_dev for two different upper dirs and will cause 'diff' to
# falsely report that content of directories is the same when it is not.
#
# This test checks that overlayfs detects and fails lookup of a multiply
# redirected dir.
#
# The check for multiply redirected dir was implemented by kernel titled
# "ovl: hash directory inodes for fsnotify"
#
#-----------------------------------------------------------------------
# Copyright (C) 2018 CTERA Networks. All Rights Reserved.
# Author: Amir Goldstein <amir73il@gmail.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.*
}
# Rename lower dir to create a redirected upper dir and
# touch lower file to create copy up with origin xattr
create_redirect()
{
local redirect=$1
mkdir -p $lowerdir/origin
touch $lowerdir/origin/file
_scratch_mount -o redirect_dir=on
touch $SCRATCH_MNT/origin/file
mv $SCRATCH_MNT/origin $SCRATCH_MNT/$redirect
$UMOUNT_PROG $SCRATCH_MNT
}
# get standard environment, filters and checks
. ./common/rc
. ./common/filter
rm -f $seqres.full
# real QA test starts here
_supported_fs overlay
_supported_os Linux
_require_scratch
_require_scratch_feature redirect_dir
# remove all files from previous runs
_scratch_mkfs
upperdir=$OVL_BASE_SCRATCH_MNT/$OVL_UPPER
lowerdir=$OVL_BASE_SCRATCH_MNT/$OVL_LOWER
# Create redirected dir with copied up file
create_redirect redirect1
# Duplicate the redirected dir and copied up file
cp -a $upperdir/redirect1 $upperdir/redirect2
# Diverge the content of the two copies of file
# and the content of two copies of redirected dir
echo right >> $upperdir/redirect1/file
touch $upperdir/redirect1/right
echo wrong >> $upperdir/redirect2/file
touch $upperdir/redirect2/wrong
_scratch_mount -o redirect_dir=on
# If both copies of file/dir use the same st_dev/st_ino in overlay
# diff won't detect that their content differs
diff -q $SCRATCH_MNT/redirect1/file $SCRATCH_MNT/redirect2/file &>/dev/null && \
echo "diff on files inside duplicate redirect parent doesn't know right from wrong!"
diff -q $SCRATCH_MNT/redirect1 $SCRATCH_MNT/redirect2 &> /dev/null && \
echo "diff on duplicate redirect dirs doesn't know right from wrong!"
# success, all done
echo "Silence is golden"
status=0
exit