tests/generic/042

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (c) 2014 Red Hat, Inc.  All Rights Reserved.
#
# FS QA Test No. 042
#
# Test stale data exposure via writeback using various file allocation
# modification commands. The presumption is that such commands result in partial
# writeback and can convert a delayed allocation extent, that might be larger
# than the ranged affected by fallocate, to a normal extent. If the fs happens
# to crash sometime between when the extent modification is logged and writeback
# occurs for dirty pages within the extent but outside of the fallocated range,
# stale data exposure can occur.
#
. ./common/preamble
_begin_fstest shutdown rw punch zero prealloc auto quick

# Import common functions.
. ./common/filter
. ./common/punch


_crashtest()
{
	cmd=$1
	img=$SCRATCH_MNT/$seq.img
	mnt=$SCRATCH_MNT/$seq.mnt
	file=$mnt/file
	size=$(_small_fs_size_mb 25)M

	# Create an fs on a small, initialized image. The pattern is written to
	# the image to detect stale data exposure.
	$XFS_IO_PROG -f -c "truncate 0" -c "pwrite -S 0xCD 0 $size" $img \
		>> $seqres.full 2>&1
	_mkfs_dev $img >> $seqres.full 2>&1

	mkdir -p $mnt
	_mount $img $mnt

	echo $cmd

	# write, run the test command and shutdown the fs
	$XFS_IO_PROG -f -c "pwrite -S 1 0 64k" -c "$cmd 60k 4k" $file | \
		_filter_xfs_io
	$here/src/godown -f $mnt

	_unmount $mnt
	_mount $img $mnt

	# We should /never/ see 0xCD in the file, because we wrote that pattern
	# to the filesystem image to expose stale data.
	if od -An -tx1 $file | grep -q "CD"; then
		echo "Saw stale data!!!"
		_hexdump $file
	fi

	_unmount $mnt
}

# Modify as appropriate.
_require_scratch
_require_scratch_shutdown
_require_xfs_io_command "falloc"
_require_xfs_io_command "fpunch"
_require_xfs_io_command "fzero"

_scratch_mkfs >/dev/null 2>&1
_require_local_device $SCRATCH_DEV
_require_metadata_journaling $SCRATCH_DEV
_scratch_mount

_crashtest "falloc -k"
_crashtest "fpunch"
_crashtest "fzero -k"

status=0
exit