common/overlay - pub/scm/linux/kernel/git/brauner/xfstests-dev - Git at Google

 #
 # overlayfs specific common functions.
 #
 . ./common/module

 # Export overlayfs xattrs and constant value
 export OVL_XATTR_OPAQUE="trusted.overlay.opaque"
 export OVL_XATTR_REDIRECT="trusted.overlay.redirect"
 export OVL_XATTR_IMPURE="trusted.overlay.impure"
 export OVL_XATTR_ORIGIN="trusted.overlay.origin"
 export OVL_XATTR_NLINK="trusted.overlay.nlink"
 export OVL_XATTR_UPPER="trusted.overlay.upper"
 export OVL_XATTR_METACOPY="trusted.overlay.metacopy"

 # helper function to do the actual overlayfs mount operation
 _overlay_mount_dirs()
 {
 	local lowerdir=$1
 	local upperdir=$2
 	local workdir=$3
 	shift 3

 	$MOUNT_PROG -t overlay -o lowerdir=$lowerdir -o upperdir=$upperdir \
 		    -o workdir=$workdir `_common_dev_mount_options $*`
 }

 # Mount with same options/mnt/dev of scratch mount, but optionally
 # with different lower/upper/work dirs
 _overlay_scratch_mount_dirs()
 {
 	local lowerdir=$1
 	local upperdir=$2
 	local workdir=$3
 	shift 3

 	_overlay_mount_dirs $lowerdir $upperdir $workdir \
 				$* $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT
 }

 _overlay_mkdirs()
 {
 	local dir=$1

 	mkdir -p $dir/$OVL_UPPER
 	mkdir -p $dir/$OVL_LOWER
 	mkdir -p $dir/$OVL_WORK
 	mkdir -p $dir/$OVL_MNT
 }

 # Given a base fs dir, set up overlay directories and mount on the given mnt.
 # The dir is used as the mount device so it can be seen from df or mount
 _overlay_mount()
 {
 	local dir=$1
 	local mnt=$2
 	shift 2

 	_supports_filetype $dir || _notrun "upper fs needs to support d_type"

 	_overlay_mkdirs $dir

 	_overlay_mount_dirs $dir/$OVL_LOWER $dir/$OVL_UPPER $dir/$OVL_WORK \
 				$* $dir $mnt
 }

 _overlay_base_mount()
 {
 	local devname=$1
 	local mntname=$2
 	local dev=$3
 	local mnt=$4
 	shift 4

 	if [ -z "$dev" -o -z "$mnt" ] || \
 		_check_mounted_on $devname $dev $mntname $mnt; then
 		_idmapped_mount $dev $mnt
 		# no base fs or already mounted
 		return 0
 	elif [ $? -ne 1 ]; then
 		# base fs mounted but not on mount point
 		return 1
 	fi

 	_mount $* $dev $mnt
 	_idmapped_mount $dev $mnt
 }

 _overlay_base_test_mount()
 {
 	_overlay_base_mount OVL_BASE_TEST_DEV OVL_BASE_TEST_DIR \
 			"$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR" \
 			$TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS
 }

 _overlay_test_mount()
 {
 	_overlay_base_test_mount && \
 		_overlay_mount $OVL_BASE_TEST_DIR $TEST_DIR $*
 }

 _overlay_base_scratch_mount()
 {
 	_overlay_base_mount OVL_BASE_SCRATCH_DEV OVL_BASE_SCRATCH_MNT \
 			"$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT" \
 			$OVL_BASE_MOUNT_OPTIONS $SELINUX_MOUNT_OPTIONS
 }

 _overlay_scratch_mount()
 {
 	if echo "$*" | grep -q remount; then
 		$MOUNT_PROG $SCRATCH_MNT $*
 		return
 	fi

 	_overlay_base_scratch_mount && \
 		_overlay_mount $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT $*
 }

 _overlay_base_unmount()
 {
 	local dev=$1
 	local mnt=$2

 	[ -n "$dev" -a -n "$mnt" ] || return 0

 	$UMOUNT_PROG $mnt
 }

 _overlay_test_unmount()
 {
 	$UMOUNT_PROG $TEST_DIR
 	_overlay_base_unmount "$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR"
 }

 _overlay_scratch_unmount()
 {
 	$UMOUNT_PROG $SCRATCH_MNT
 	_overlay_base_unmount "$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT"
 }

 # Check that a specific overlayfs feature is supported
 _check_overlay_feature()
 {
 	local feature=$1
 	local dev=$2
 	local mnt=$3

 	# overalyfs features (e.g. redirect_dir, index) are
 	# configurable from Kconfig (the build default), by module
 	# parameter (the system default) and per mount by mount
 	# option ${feature}=[on|off].
 	local default=`_get_fs_module_param ${feature}`
 	[ "$default" = Y ] || [ "$default" = N ] || \
 		_notrun "feature '${feature}' not supported by ${FSTYP}"

 	# Check options to be sure. For example, Overlayfs will fallback to
 	# index=off if underlying fs does not support file handles.
 	# Overlayfs only displays mount option if it differs from the default.
 	# Overlayfs may enable the feature, but fallback to read-only mount.
 	((( [ "$default" = N ] && _fs_options $dev | grep -q "${feature}=on" ) || \
 	  ( [ "$default" = Y ] && ! _fs_options $dev | grep -q "${feature}=off" )) && \
 	    touch $mnt/foo 2>/dev/null ) || \
 	        _notrun "${FSTYP} feature '${feature}' cannot be enabled on ${dev}"
 }

 # Require a set of overlayfs features
 _require_scratch_overlay_features()
 {
 	local features=( $* )
 	local opts="rw"

 	for feature in ${features[*]}; do
 		# If the module parameter does not exist then there is no
 		# point in checking the mount option.
 		_get_fs_module_param ${feature} > /dev/null 2>&1 || \
 			_notrun "feature '${feature}' not supported by overlay"
 		opts+=",${feature}=on"
 	done

 	_scratch_mkfs > /dev/null 2>&1
 	_try_scratch_mount -o $opts || \
 	        _notrun "overlay features '${features[*]}' cannot be enabled on ${SCRATCH_DEV}"

 	for feature in ${features[*]}; do
 		_check_overlay_feature ${feature} $SCRATCH_DEV $SCRATCH_MNT
 	done

 	_scratch_unmount
 }

 # Helper function to check underlying dirs of overlay filesystem
 _overlay_fsck_dirs()
 {
 	local lowerdir=$1
 	local upperdir=$2
 	local workdir=$3
 	shift 3

 	[[ ! -x "$FSCK_OVERLAY_PROG" ]] && return 0

 	$FSCK_OVERLAY_PROG -o lowerdir=$lowerdir -o upperdir=$upperdir \
 			   -o workdir=$workdir $*
 }

 # Run fsck and check for expected return value
 _overlay_fsck_expect()
 {
 	# The first arguments is the expected fsck program exit code, the
 	# remaining arguments are the input parameters of the fsck program.
 	local expect_ret=$1
 	local lowerdir=$2
 	local upperdir=$3
 	local workdir=$4
 	shift 4

 	_overlay_fsck_dirs $lowerdir $upperdir $workdir $* >> \
 			$seqres.full 2>&1
 	fsck_ret=$?

 	[[ "$fsck_ret" == "$expect_ret" ]] || \
 		echo "expect fsck.overlay to return $expect_ret, but got $fsck_ret"
 }

 _overlay_check_dirs()
 {
 	local lowerdir=$1
 	local upperdir=$2
 	local workdir=$3
 	shift 3
 	local err=0

 	_overlay_fsck_dirs $lowerdir $upperdir $workdir \
 			   $FSCK_OPTIONS $* >>$tmp.fsck 2>&1
 	if [ $? -ne 0 ]; then
 		_log_err "_overlay_check_fs: overlayfs on $lowerdir,$upperdir,$workdir is inconsistent"

 		echo "*** fsck.overlay output ***"	>>$seqres.full
 		cat $tmp.fsck				>>$seqres.full
 		echo "*** end fsck.overlay output"	>>$seqres.full

 		echo "*** mount output ***"		>>$seqres.full
 		_mount					>>$seqres.full
 		echo "*** end mount output"		>>$seqres.full

 		err=1
 	fi
 	rm -f $tmp.fsck

 	return $err
 }

 # Check the same mnt/dev of _check_overlay_scratch_fs but non-default
 # underlying scratch dirs of overlayfs, it needs lower/upper/work dirs
 # provided as arguments, and it's useful for non-default setups such
 # as multiple lower layers
 _overlay_check_scratch_dirs()
 {
 	local lowerdir=$1
 	local upperdir=$2
 	local workdir=$3
 	shift 3

 	# Need to umount overlay for scratch dir check
 	local ovl_mounted=`_is_dir_mountpoint $SCRATCH_MNT`
 	[ -z "$ovl_mounted" ] || $UMOUNT_PROG $SCRATCH_MNT

 	# Check dirs with extra overlay options
 	_overlay_check_dirs $lowerdir $upperdir $workdir $*
 	local ret=$?

 	if [ $ret -eq 0 -a -n "$ovl_mounted" ]; then
 		# overlay was mounted, remount with extra mount options
 		_overlay_scratch_mount_dirs $lowerdir $upperdir \
 					    $workdir $*
 		ret=$?
 	fi

 	return $ret
 }

 _overlay_check_fs()
 {
 	# The first arguments is overlay mount point use for checking
 	# overlay filesystem is mounted or not, the remaining arquments
 	# use for mounting overlay base filesystem if it was not mounted.
 	# We shift one to aligns arguments for _overlay_base_mount.
 	local ovl_mnt=$1
 	shift 1

 	local base_dev=$3
 	local base_mnt=$4

 	[ "$FSTYP" = overlay ] || return 0

 	# Base fs needs to be mounted to check overlay dirs
 	local base_fstype=""
 	local ovl_mounted=""

 	[ -z "$base_dev" ] || \
 		base_fstype=`_fs_type $base_dev`

 	# If base_dev is set but base_fstype is empty, base fs is not
 	# mounted, we need to mount base fs. Otherwise, we need to
 	# check and umount overlayfs if it was mounted.
 	if [ -n "$base_dev" -a -z "$base_fstype" ]; then
 		_overlay_base_mount $*
 	else
 		# Check and umount overlay for dir check
 		ovl_mounted=`_is_dir_mountpoint $ovl_mnt`
 		[ -z "$ovl_mounted" ] || $UMOUNT_PROG $ovl_mnt
 	fi

 	_overlay_check_dirs $base_mnt/$OVL_LOWER $base_mnt/$OVL_UPPER \
 			    $base_mnt/$OVL_WORK
 	local ret=$?

 	if [ -n "$base_dev" -a -z "$base_fstype" ]; then
 		_overlay_base_unmount "$base_dev" "$base_mnt"
 	elif [ $ret -eq 0 -a -n "$ovl_mounted" ]; then
 		# overlay was mounted, remount besides extra mount options
 		_overlay_mount $base_mnt $ovl_mnt
 		ret=$?
 	fi

 	if [ $ret != 0 ]; then
 		status=1
 		if [ "$iam" != "check" ]; then
 			exit 1
 		fi
 		return 1
 	fi

 	return 0
 }

 _check_overlay_test_fs()
 {
 	_overlay_check_fs "$TEST_DIR" \
 		OVL_BASE_TEST_DEV OVL_BASE_TEST_DIR \
 		"$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR" \
 		$TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS
 }

 _check_overlay_scratch_fs()
 {
 	_overlay_check_fs "$SCRATCH_MNT" \
 		OVL_BASE_SCRATCH_DEV OVL_BASE_SCRATCH_MNT \
 		"$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT" \
 		$OVL_BASE_MOUNT_OPTIONS $SELINUX_MOUNT_OPTIONS
 }

 _repair_overlay_scratch_fs()
 {
 	_overlay_fsck_dirs $OVL_BASE_SCRATCH_MNT/$OVL_LOWER \
 		$OVL_BASE_SCRATCH_MNT/$OVL_UPPER \
 		$OVL_BASE_SCRATCH_MNT/$OVL_WORK -y
 	local res=$?
 	case $res in
 	$FSCK_OK|$FSCK_NONDESTRUCT)
 		res=0
 		;;
 	*)
 		_dump_err2 "fsck.overlay failed, err=$res"
 		;;
 	esac
 	return $res
 }

 # This test requires that unionmount testsuite is installed at
 # $UNIONMOUNT_TESTSUITE and that it supports configuring layers and overlay
 # mount paths via UNIONMOUNT_* environment variables.
 _require_unionmount_testsuite()
 {
 	[ -x "$UNIONMOUNT_TESTSUITE/run" ] || \
 		_notrun "unionmount testsuite required."

 	# Verify that UNIONMOUNT_* vars are supported
 	local usage=`UNIONMOUNT_BASEDIR=_ "$UNIONMOUNT_TESTSUITE/run" 2>&1`
 	echo $usage | grep -wq "UNIONMOUNT_BASEDIR" || \
 		_notrun "newer version of unionmount testsuite required."

 	[ -n "$OVERLAY_MOUNT_OPTIONS" ] || return
 	# If custom overlay mount options are used
 	# verify that UNIONMOUNT_MNTOPTIONS var is supported
 	local usage=`UNIONMOUNT_MNTOPTIONS=_ "$UNIONMOUNT_TESTSUITE/run" 2>&1`
 	echo $usage | grep -wq "UNIONMOUNT_MNTOPTIONS" || \
 		_notrun "newer version of unionmount testsuite required to support OVERLAY_MOUNT_OPTIONS."
 }

 _unionmount_testsuite_run()
 {
 	[ "$FSTYP" = overlay ] || \
 		_notrun "Filesystem $FSTYP not supported with unionmount testsuite."

 	# Provide the mounted base fs for upper and lower dirs and the
 	# overlay mount point.
 	# unionmount testsuite will perform the overlay mount.
 	# test fs is used for lower layer in non-samefs runs.
 	# scratch fs is used for upper layer in non-samefs runs and
 	# for both layers in samefs runs.
 	if (echo $* | grep -qv samefs) ; then
 		_overlay_base_test_mount
 		export UNIONMOUNT_LOWERDIR=$OVL_BASE_TEST_DIR/union
 	fi
 	export UNIONMOUNT_BASEDIR=$OVL_BASE_SCRATCH_MNT/union
 	export UNIONMOUNT_MNTOPTIONS="$OVERLAY_MOUNT_OPTIONS"

 	_scratch_mkfs
 	rm -rf $UNIONMOUNT_BASEDIR $UNIONMOUNT_LOWERDIR
 	mkdir -p $UNIONMOUNT_BASEDIR $UNIONMOUNT_LOWERDIR

 	cd $UNIONMOUNT_TESTSUITE
 	echo "run $* ..." > $seqres.full
 	./run $* >> $seqres.full || \
 		echo "unionmount testsuite failed! see $seqres.full for details."
 }

 _unionmount_testsuite_cleanup()
 {
 	cd /
 	rm -f $tmp.*

 	[ -n "$UNIONMOUNT_BASEDIR" ] || return 0

 	# Cleanup overlay mount after unionmount testsuite run
 	cd $UNIONMOUNT_TESTSUITE
 	echo "run --clean-up ..." >> $seqres.full
 	./run --clean-up >> $seqres.full 2>&1
 }
	#
	# overlayfs specific common functions.
	#
	. ./common/module

	# Export overlayfs xattrs and constant value
	export OVL_XATTR_OPAQUE="trusted.overlay.opaque"
	export OVL_XATTR_REDIRECT="trusted.overlay.redirect"
	export OVL_XATTR_IMPURE="trusted.overlay.impure"
	export OVL_XATTR_ORIGIN="trusted.overlay.origin"
	export OVL_XATTR_NLINK="trusted.overlay.nlink"
	export OVL_XATTR_UPPER="trusted.overlay.upper"
	export OVL_XATTR_METACOPY="trusted.overlay.metacopy"

	# helper function to do the actual overlayfs mount operation
	_overlay_mount_dirs()
	{
	local lowerdir=$1
	local upperdir=$2
	local workdir=$3
	shift 3

	$MOUNT_PROG -t overlay -o lowerdir=$lowerdir -o upperdir=$upperdir \
	-o workdir=$workdir `_common_dev_mount_options $*`
	}

	# Mount with same options/mnt/dev of scratch mount, but optionally
	# with different lower/upper/work dirs
	_overlay_scratch_mount_dirs()
	{
	local lowerdir=$1
	local upperdir=$2
	local workdir=$3
	shift 3

	_overlay_mount_dirs $lowerdir $upperdir $workdir \
	$* $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT
	}

	_overlay_mkdirs()
	{
	local dir=$1

	mkdir -p $dir/$OVL_UPPER
	mkdir -p $dir/$OVL_LOWER
	mkdir -p $dir/$OVL_WORK
	mkdir -p $dir/$OVL_MNT
	}

	# Given a base fs dir, set up overlay directories and mount on the given mnt.
	# The dir is used as the mount device so it can be seen from df or mount
	_overlay_mount()
	{
	local dir=$1
	local mnt=$2
	shift 2

	_supports_filetype $dir \|\| _notrun "upper fs needs to support d_type"

	_overlay_mkdirs $dir

	_overlay_mount_dirs $dir/$OVL_LOWER $dir/$OVL_UPPER $dir/$OVL_WORK \
	$* $dir $mnt
	}

	_overlay_base_mount()
	{
	local devname=$1
	local mntname=$2
	local dev=$3
	local mnt=$4
	shift 4

	if [ -z "$dev" -o -z "$mnt" ] \|\| \
	_check_mounted_on $devname $dev $mntname $mnt; then
	_idmapped_mount $dev $mnt
	# no base fs or already mounted
	return 0
	elif [ $? -ne 1 ]; then
	# base fs mounted but not on mount point
	return 1
	fi

	_mount $* $dev $mnt
	_idmapped_mount $dev $mnt
	}

	_overlay_base_test_mount()
	{
	_overlay_base_mount OVL_BASE_TEST_DEV OVL_BASE_TEST_DIR \
	"$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR" \
	$TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS
	}

	_overlay_test_mount()
	{
	_overlay_base_test_mount && \
	_overlay_mount $OVL_BASE_TEST_DIR $TEST_DIR $*
	}

	_overlay_base_scratch_mount()
	{
	_overlay_base_mount OVL_BASE_SCRATCH_DEV OVL_BASE_SCRATCH_MNT \
	"$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT" \
	$OVL_BASE_MOUNT_OPTIONS $SELINUX_MOUNT_OPTIONS
	}

	_overlay_scratch_mount()
	{
	if echo "$*" \| grep -q remount; then
	$MOUNT_PROG $SCRATCH_MNT $*
	return
	fi

	_overlay_base_scratch_mount && \
	_overlay_mount $OVL_BASE_SCRATCH_MNT $SCRATCH_MNT $*
	}

	_overlay_base_unmount()
	{
	local dev=$1
	local mnt=$2

	[ -n "$dev" -a -n "$mnt" ] \|\| return 0

	$UMOUNT_PROG $mnt
	}

	_overlay_test_unmount()
	{
	$UMOUNT_PROG $TEST_DIR
	_overlay_base_unmount "$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR"
	}

	_overlay_scratch_unmount()
	{
	$UMOUNT_PROG $SCRATCH_MNT
	_overlay_base_unmount "$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT"
	}

	# Check that a specific overlayfs feature is supported
	_check_overlay_feature()
	{
	local feature=$1
	local dev=$2
	local mnt=$3

	# overalyfs features (e.g. redirect_dir, index) are
	# configurable from Kconfig (the build default), by module
	# parameter (the system default) and per mount by mount
	# option ${feature}=[on\|off].
	local default=`_get_fs_module_param ${feature}`
	[ "$default" = Y ] \|\| [ "$default" = N ] \|\| \
	_notrun "feature '${feature}' not supported by ${FSTYP}"

	# Check options to be sure. For example, Overlayfs will fallback to
	# index=off if underlying fs does not support file handles.
	# Overlayfs only displays mount option if it differs from the default.
	# Overlayfs may enable the feature, but fallback to read-only mount.
	((( [ "$default" = N ] && _fs_options $dev \| grep -q "${feature}=on" ) \|\| \
	( [ "$default" = Y ] && ! _fs_options $dev \| grep -q "${feature}=off" )) && \
	touch $mnt/foo 2>/dev/null ) \|\| \
	_notrun "${FSTYP} feature '${feature}' cannot be enabled on ${dev}"
	}

	# Require a set of overlayfs features
	_require_scratch_overlay_features()
	{
	local features=( $* )
	local opts="rw"

	for feature in ${features[*]}; do
	# If the module parameter does not exist then there is no
	# point in checking the mount option.
	_get_fs_module_param ${feature} > /dev/null 2>&1 \|\| \
	_notrun "feature '${feature}' not supported by overlay"
	opts+=",${feature}=on"
	done

	_scratch_mkfs > /dev/null 2>&1
	_try_scratch_mount -o $opts \|\| \
	_notrun "overlay features '${features[*]}' cannot be enabled on ${SCRATCH_DEV}"

	for feature in ${features[*]}; do
	_check_overlay_feature ${feature} $SCRATCH_DEV $SCRATCH_MNT
	done

	_scratch_unmount
	}

	# Helper function to check underlying dirs of overlay filesystem
	_overlay_fsck_dirs()
	{
	local lowerdir=$1
	local upperdir=$2
	local workdir=$3
	shift 3

	[[ ! -x "$FSCK_OVERLAY_PROG" ]] && return 0

	$FSCK_OVERLAY_PROG -o lowerdir=$lowerdir -o upperdir=$upperdir \
	-o workdir=$workdir $*
	}

	# Run fsck and check for expected return value
	_overlay_fsck_expect()
	{
	# The first arguments is the expected fsck program exit code, the
	# remaining arguments are the input parameters of the fsck program.
	local expect_ret=$1
	local lowerdir=$2
	local upperdir=$3
	local workdir=$4
	shift 4

	_overlay_fsck_dirs $lowerdir $upperdir $workdir $* >> \
	$seqres.full 2>&1
	fsck_ret=$?

	[[ "$fsck_ret" == "$expect_ret" ]] \|\| \
	echo "expect fsck.overlay to return $expect_ret, but got $fsck_ret"
	}

	_overlay_check_dirs()
	{
	local lowerdir=$1
	local upperdir=$2
	local workdir=$3
	shift 3
	local err=0

	_overlay_fsck_dirs $lowerdir $upperdir $workdir \
	$FSCK_OPTIONS $* >>$tmp.fsck 2>&1
	if [ $? -ne 0 ]; then
	_log_err "_overlay_check_fs: overlayfs on $lowerdir,$upperdir,$workdir is inconsistent"

	echo "* fsck.overlay output *" >>$seqres.full
	cat $tmp.fsck >>$seqres.full
	echo "*** end fsck.overlay output" >>$seqres.full

	echo "* mount output *" >>$seqres.full
	_mount >>$seqres.full
	echo "*** end mount output" >>$seqres.full

	err=1
	fi
	rm -f $tmp.fsck

	return $err
	}

	# Check the same mnt/dev of _check_overlay_scratch_fs but non-default
	# underlying scratch dirs of overlayfs, it needs lower/upper/work dirs
	# provided as arguments, and it's useful for non-default setups such
	# as multiple lower layers
	_overlay_check_scratch_dirs()
	{
	local lowerdir=$1
	local upperdir=$2
	local workdir=$3
	shift 3

	# Need to umount overlay for scratch dir check
	local ovl_mounted=`_is_dir_mountpoint $SCRATCH_MNT`
	[ -z "$ovl_mounted" ] \|\| $UMOUNT_PROG $SCRATCH_MNT

	# Check dirs with extra overlay options
	_overlay_check_dirs $lowerdir $upperdir $workdir $*
	local ret=$?

	if [ $ret -eq 0 -a -n "$ovl_mounted" ]; then
	# overlay was mounted, remount with extra mount options
	_overlay_scratch_mount_dirs $lowerdir $upperdir \
	$workdir $*
	ret=$?
	fi

	return $ret
	}

	_overlay_check_fs()
	{
	# The first arguments is overlay mount point use for checking
	# overlay filesystem is mounted or not, the remaining arquments
	# use for mounting overlay base filesystem if it was not mounted.
	# We shift one to aligns arguments for _overlay_base_mount.
	local ovl_mnt=$1
	shift 1

	local base_dev=$3
	local base_mnt=$4

	[ "$FSTYP" = overlay ] \|\| return 0

	# Base fs needs to be mounted to check overlay dirs
	local base_fstype=""
	local ovl_mounted=""

	[ -z "$base_dev" ] \|\| \
	base_fstype=`_fs_type $base_dev`

	# If base_dev is set but base_fstype is empty, base fs is not
	# mounted, we need to mount base fs. Otherwise, we need to
	# check and umount overlayfs if it was mounted.
	if [ -n "$base_dev" -a -z "$base_fstype" ]; then
	_overlay_base_mount $*
	else
	# Check and umount overlay for dir check
	ovl_mounted=`_is_dir_mountpoint $ovl_mnt`
	[ -z "$ovl_mounted" ] \|\| $UMOUNT_PROG $ovl_mnt
	fi

	_overlay_check_dirs $base_mnt/$OVL_LOWER $base_mnt/$OVL_UPPER \
	$base_mnt/$OVL_WORK
	local ret=$?

	if [ -n "$base_dev" -a -z "$base_fstype" ]; then
	_overlay_base_unmount "$base_dev" "$base_mnt"
	elif [ $ret -eq 0 -a -n "$ovl_mounted" ]; then
	# overlay was mounted, remount besides extra mount options
	_overlay_mount $base_mnt $ovl_mnt
	ret=$?
	fi

	if [ $ret != 0 ]; then
	status=1
	if [ "$iam" != "check" ]; then
	exit 1
	fi
	return 1
	fi

	return 0
	}

	_check_overlay_test_fs()
	{
	_overlay_check_fs "$TEST_DIR" \
	OVL_BASE_TEST_DEV OVL_BASE_TEST_DIR \
	"$OVL_BASE_TEST_DEV" "$OVL_BASE_TEST_DIR" \
	$TEST_FS_MOUNT_OPTS $SELINUX_MOUNT_OPTIONS
	}

	_check_overlay_scratch_fs()
	{
	_overlay_check_fs "$SCRATCH_MNT" \
	OVL_BASE_SCRATCH_DEV OVL_BASE_SCRATCH_MNT \
	"$OVL_BASE_SCRATCH_DEV" "$OVL_BASE_SCRATCH_MNT" \
	$OVL_BASE_MOUNT_OPTIONS $SELINUX_MOUNT_OPTIONS
	}

	_repair_overlay_scratch_fs()
	{
	_overlay_fsck_dirs $OVL_BASE_SCRATCH_MNT/$OVL_LOWER \
	$OVL_BASE_SCRATCH_MNT/$OVL_UPPER \
	$OVL_BASE_SCRATCH_MNT/$OVL_WORK -y
	local res=$?
	case $res in
	$FSCK_OK\|$FSCK_NONDESTRUCT)
	res=0
	;;
	*)
	_dump_err2 "fsck.overlay failed, err=$res"
	;;
	esac
	return $res
	}

	# This test requires that unionmount testsuite is installed at
	# $UNIONMOUNT_TESTSUITE and that it supports configuring layers and overlay
	# mount paths via UNIONMOUNT_* environment variables.
	_require_unionmount_testsuite()
	{
	[ -x "$UNIONMOUNT_TESTSUITE/run" ] \|\| \
	_notrun "unionmount testsuite required."

	# Verify that UNIONMOUNT_* vars are supported
	local usage=`UNIONMOUNT_BASEDIR=_ "$UNIONMOUNT_TESTSUITE/run" 2>&1`
	echo $usage \| grep -wq "UNIONMOUNT_BASEDIR" \|\| \
	_notrun "newer version of unionmount testsuite required."

	[ -n "$OVERLAY_MOUNT_OPTIONS" ] \|\| return
	# If custom overlay mount options are used
	# verify that UNIONMOUNT_MNTOPTIONS var is supported
	local usage=`UNIONMOUNT_MNTOPTIONS=_ "$UNIONMOUNT_TESTSUITE/run" 2>&1`
	echo $usage \| grep -wq "UNIONMOUNT_MNTOPTIONS" \|\| \
	_notrun "newer version of unionmount testsuite required to support OVERLAY_MOUNT_OPTIONS."
	}

	_unionmount_testsuite_run()
	{
	[ "$FSTYP" = overlay ] \|\| \
	_notrun "Filesystem $FSTYP not supported with unionmount testsuite."

	# Provide the mounted base fs for upper and lower dirs and the
	# overlay mount point.
	# unionmount testsuite will perform the overlay mount.
	# test fs is used for lower layer in non-samefs runs.
	# scratch fs is used for upper layer in non-samefs runs and
	# for both layers in samefs runs.
	if (echo $* \| grep -qv samefs) ; then
	_overlay_base_test_mount
	export UNIONMOUNT_LOWERDIR=$OVL_BASE_TEST_DIR/union
	fi
	export UNIONMOUNT_BASEDIR=$OVL_BASE_SCRATCH_MNT/union
	export UNIONMOUNT_MNTOPTIONS="$OVERLAY_MOUNT_OPTIONS"

	_scratch_mkfs
	rm -rf $UNIONMOUNT_BASEDIR $UNIONMOUNT_LOWERDIR
	mkdir -p $UNIONMOUNT_BASEDIR $UNIONMOUNT_LOWERDIR

	cd $UNIONMOUNT_TESTSUITE
	echo "run $* ..." > $seqres.full
	./run $* >> $seqres.full \|\| \
	echo "unionmount testsuite failed! see $seqres.full for details."
	}

	_unionmount_testsuite_cleanup()
	{
	cd /
	rm -f $tmp.*

	[ -n "$UNIONMOUNT_BASEDIR" ] \|\| return 0

	# Cleanup overlay mount after unionmount testsuite run
	cd $UNIONMOUNT_TESTSUITE
	echo "run --clean-up ..." >> $seqres.full
	./run --clean-up >> $seqres.full 2>&1
	}