#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 CTERA Networks. All Rights Reserved.
#
# FS QA Test 065
#
# Test mount error cases with overlapping layers
#
# - Same upperdir/lowerdir
# - Overlapping upperdir/lowerdir
# - Overlapping lowerdir layers
# - Overlapping lowerdir with other mount upperdir/workdir
#
# Overlapping layers on mount or lookup results in ELOOP.
# Overlapping lowerdir with other mount upperdir/workdir
# result in EBUSY (only if index=on is used).
#
# This is a regression test for kernel commit:
#
#    146d62e5a586 "ovl: detect overlapping layers"
#
# and its followup fix commit:
#    0be0bfd2de9d "ovl: fix regression caused by overlapping layers detection"
#
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.*
	$UMOUNT_PROG $mnt2 2>/dev/null
}

# 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
# Use non-default scratch underlying overlay dirs, we need to check
# them explicity after test.
_require_scratch_nocheck
_require_scratch_feature index

# Remove all files from previous tests
_scratch_mkfs

# Create multiple lowerdirs, upperdirs and workdirs
basedir=$OVL_BASE_SCRATCH_MNT
lowerdir=$basedir/lower
upperdir=$basedir/upper
workdir=$basedir/workdir
upperdir2=$basedir/upper.2
workdir2=$basedir/workdir.2
mnt2=$basedir/mnt.2

mkdir -p $lowerdir/lower $upperdir $workdir

# Try to mount an overlay with the same upperdir/lowerdir - expect ELOOP
echo Conflicting upperdir/lowerdir
_overlay_scratch_mount_dirs $upperdir $upperdir $workdir \
	2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

# Use new upper/work dirs for each test to avoid ESTALE errors
# on mismatch lowerdir/upperdir (see test overlay/037)
rm -rf $upperdir $workdir
mkdir $upperdir $workdir

# Try to mount an overlay with the same workdir/lowerdir - expect ELOOP
# because $workdir/work overlaps with lowerdir
echo Conflicting workdir/lowerdir
_overlay_scratch_mount_dirs $workdir $upperdir $workdir \
	-oindex=off 2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir $workdir
mkdir -p $upperdir/lower $workdir

# Try to mount an overlay with overlapping upperdir/lowerdir - expect ELOOP
# upperdir inside lowerdir is allowed, lowerdir inside upperdir is not allowed
echo Overlapping upperdir/lowerdir
_overlay_scratch_mount_dirs $upperdir/lower $upperdir $workdir \
	2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir $workdir
mkdir $upperdir $workdir

# Try to mount an overlay with the same lower layers - expect ELOOP
echo Conflicting lower layers
_overlay_scratch_mount_dirs $lowerdir:$lowerdir $upperdir $workdir \
	2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir $workdir
mkdir $upperdir $workdir

# Try to mount an overlay with overlapping lower layers - expect ELOOP
echo Overlapping lower layers below
_overlay_scratch_mount_dirs $lowerdir:$lowerdir/lower $upperdir $workdir \
	2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir $workdir
mkdir $upperdir $workdir

# Try to mount an overlay with overlapping lower layers - expect ELOOP
echo Overlapping lower layers above
_overlay_scratch_mount_dirs $lowerdir/lower:$lowerdir $upperdir $workdir \
	2>&1 | _filter_error_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir $workdir
mkdir -p $upperdir/upper $workdir $mnt2

# Mount overlay with non overlapping lowerdir, upperdir, workdir -
# expect success
_overlay_mount_dirs $lowerdir $upperdir $workdir overlay $mnt2

rm -rf $upperdir2 $workdir2
mkdir -p $upperdir2 $workdir2 $mnt2

# Try to mount an overlay with layers overlapping with another overlayfs
# upperdir - expect EBUSY with index=on and success with index=off
echo "Overlapping with upperdir of another instance (index=on)"
_overlay_scratch_mount_dirs $upperdir/upper $upperdir2 $workdir2 \
	-oindex=on 2>&1 | _filter_busy_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir2 $workdir2
mkdir -p $upperdir2 $workdir2

echo "Overlapping with upperdir of another instance (index=off)"
_overlay_scratch_mount_dirs $upperdir/upper $upperdir2 $workdir2 \
	-oindex=off && $UMOUNT_PROG $SCRATCH_MNT

rm -rf $upperdir2 $workdir2
mkdir -p $upperdir2 $workdir2

# Try to mount an overlay with layers overlapping with another overlayfs
# workdir - expect EBUSY with index=on and success with index=off
echo "Overlapping with workdir of another instance (index=on)"
_overlay_scratch_mount_dirs $workdir/work $upperdir2 $workdir2 \
	-oindex=on 2>&1 | _filter_busy_mount
$UMOUNT_PROG $SCRATCH_MNT 2>/dev/null

rm -rf $upperdir2 $workdir2
mkdir -p $upperdir2 $workdir2

echo "Overlapping with workdir of another instance (index=off)"
_overlay_scratch_mount_dirs $workdir/work $upperdir2 $workdir2 \
	-oindex=off && $UMOUNT_PROG $SCRATCH_MNT

# Move upper layer root into lower layer after mount
echo Overlapping upperdir/lowerdir after mount
mv $upperdir $lowerdir/
# Lookup files in overlay mount with overlapping layers -
# expect ELOOP when upper layer root is found in lower layer
find $mnt2/upper 2>&1 | _filter_scratch

# success, all done
status=0
exit