common/metadump

##/bin/bash
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (c) 2024 Oracle.  All Rights Reserved.
#
# Filesystem metadata dump testing functions.
#

# Set up environment variables for a metadump test.  Requires the test and
# scratch devices.  Sets XFS_METADUMP_{FILE,IMG} and MAX_XFS_METADUMP_VERSION.
_xfs_setup_verify_metadump()
{
	XFS_METADUMP_FILE="$TEST_DIR/${seq}_metadump"
	XFS_METADUMP_IMG="$TEST_DIR/${seq}_image"
	MAX_XFS_METADUMP_VERSION="$(_xfs_metadump_max_version)"

	rm -f "$XFS_METADUMP_FILE" "$XFS_METADUMP_IMG"*
}

_xfs_cleanup_verify_metadump()
{
	local img

	_scratch_unmount &>> $seqres.full

	test -n "$XFS_METADUMP_FILE" && rm -f "$XFS_METADUMP_FILE"

	if [ -n "$XFS_METADUMP_IMG" ]; then
		losetup -n -a -O BACK-FILE,NAME | grep "^$XFS_METADUMP_IMG" | while read backing ldev; do
			losetup -d "$ldev"
		done

		# Don't call rm directly with a globbed argument here to avoid
		# issues issues with variable expansions.
		for img in "$XFS_METADUMP_IMG"*; do
			test -e "$img" && rm -f "$img"
		done
	fi
}

# Can xfs_metadump snapshot the fs metadata to a v1 metadump file?
_scratch_xfs_can_metadump_v1()
{
	# metadump v1 does not support log devices
	[ "$USE_EXTERNAL" = yes ] && [ -n "$SCRATCH_LOGDEV" ] && return 1

	# metadump v1 does not support realtime devices
	[ "$USE_EXTERNAL" = yes ] && [ -n "$SCRATCH_RTDEV" ] && return 1

	return 0
}

# Can xfs_metadump snapshot the fs metadata to a v2 metadump file?
_scratch_xfs_can_metadump_v2()
{
	test "$MAX_XFS_METADUMP_VERSION" -ge 2
}

# Create a metadump in v1 format, restore it to fs image files, then mount the
# images and fsck them.
_xfs_verify_metadump_v1()
{
	local metadump_args="$1"
	local extra_test="$2"

	local metadump_file="$XFS_METADUMP_FILE"
	local version=""
	local data_img="$XFS_METADUMP_IMG.data"
	local data_loop

	# Force v1 if we detect v2 support
	if [[ $MAX_XFS_METADUMP_FORMAT > 1 ]]; then
		version="-v 1"
	fi

	# Capture metadump, which creates metadump_file
	_scratch_xfs_metadump $metadump_file $metadump_args $version

	# Restore metadump, which creates data_img
	SCRATCH_DEV=$data_img _scratch_xfs_mdrestore $metadump_file

	# Create loopdev for data device so we can mount the fs
	data_loop=$(_create_loop_device $data_img)

	# Mount fs, run an extra test, fsck, and unmount
	SCRATCH_DEV=$data_loop _scratch_mount
	if [ -n "$extra_test" ]; then
		SCRATCH_DEV=$data_loop $extra_test
	fi
	SCRATCH_DEV=$data_loop _check_xfs_scratch_fs
	SCRATCH_DEV=$data_loop _scratch_unmount

	# Tear down what we created
	_destroy_loop_device $data_loop
	rm -f $data_img
}

# Create a metadump in v2 format, restore it to fs image files, then mount the
# images and fsck them.
_xfs_verify_metadump_v2()
{
	local metadump_args="$1"
	local extra_test="$2"

	local metadump_file="$XFS_METADUMP_FILE"
	local version="-v 2"
	local data_img="$XFS_METADUMP_IMG.data"
	local data_loop
	local log_img=""
	local log_loop

	# Capture metadump, which creates metadump_file
	_scratch_xfs_metadump $metadump_file $metadump_args $version

	#
	# Metadump v2 files can contain contents dumped from an external log
	# device. Use a temporary file to hold the log device contents restored
	# from such a metadump file.
	test -n "$SCRATCH_LOGDEV" && log_img="$XFS_METADUMP_IMG.log"

	# Restore metadump, which creates data_img and log_img
	SCRATCH_DEV=$data_img SCRATCH_LOGDEV=$log_img \
		_scratch_xfs_mdrestore $metadump_file

	# Create loopdev for data device so we can mount the fs
	data_loop=$(_create_loop_device $data_img)

	# Create loopdev for log device if we recovered anything
	test -s "$log_img" && log_loop=$(_create_loop_device $log_img)

	# Mount fs, run an extra test, fsck, and unmount
	SCRATCH_DEV=$data_loop SCRATCH_LOGDEV=$log_loop _scratch_mount
	if [ -n "$extra_test" ]; then
		SCRATCH_DEV=$data_loop SCRATCH_LOGDEV=$log_loop $extra_test
	fi
	SCRATCH_DEV=$data_loop SCRATCH_LOGDEV=$log_loop _check_xfs_scratch_fs
	SCRATCH_DEV=$data_loop _scratch_unmount

	# Tear down what we created
	if [ -b "$log_loop" ]; then
		_destroy_loop_device $log_loop
		rm -f $log_img
	fi
	_destroy_loop_device $data_loop
	rm -f $data_img
}

# Verify both metadump formats if possible
_xfs_verify_metadumps()
{
	_scratch_xfs_can_metadump_v1 && _xfs_verify_metadump_v1 "$@"
	_scratch_xfs_can_metadump_v2 && _xfs_verify_metadump_v2 "$@"
}