#! /bin/bash
# FSQA Test No. 101
#
# Test that if we truncate a file to a smaller size, then truncate it to its
# original size or a larger size, then fsyncing it and a power failure happens,
# the file will have the range [first_truncate_size, last_size[ with all bytes
# having a value of 0x00 if we read it the next time the filesystem is mounted.
#
# This test is motivated by a bug found in btrfs.
#
#-----------------------------------------------------------------------
#
# Copyright (C) 2015 SUSE Linux Products GmbH. All Rights Reserved.
# Author: Filipe Manana <fdmanana@suse.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"
tmp=/tmp/$$
status=1	# failure is the default!
trap "_cleanup; exit \$status" 0 1 2 3 15

_cleanup()
{
	_cleanup_flakey
	rm -f $tmp.*
}

# get standard environment, filters and checks
. ./common/rc
. ./common/filter
. ./common/dmflakey

# real QA test starts here
_supported_fs generic
_supported_os Linux
_require_scratch
_require_dm_target flakey
_require_metadata_journaling $SCRATCH_DEV

# This test was motivated by an issue found in btrfs when the btrfs no-holes
# feature is enabled (introduced in kernel 3.14). So enable the feature if the
# fs being tested is btrfs.
if [ $FSTYP == "btrfs" ]; then
	_require_btrfs_fs_feature "no_holes"
	_require_btrfs_mkfs_feature "no-holes"
	MKFS_OPTIONS="$MKFS_OPTIONS -O no-holes"
fi

rm -f $seqres.full

_scratch_mkfs >>$seqres.full 2>&1
_init_flakey
_mount_flakey

# Create our test files and make sure everything is durably persisted.
$XFS_IO_PROG -f -c "pwrite -S 0xaa 0 64K"         \
		-c "pwrite -S 0xbb 64K 61K"       \
		$SCRATCH_MNT/foo | _filter_xfs_io
$XFS_IO_PROG -f -c "pwrite -S 0xee 0 64K"         \
		-c "pwrite -S 0xff 64K 61K"       \
		$SCRATCH_MNT/bar | _filter_xfs_io
sync

# Now truncate our file foo to a smaller size (64Kb) and then truncate it to the
# size it had before the shrinking truncate (125Kb). Then fsync our file. If a
# power failure happens after the fsync, we expect our file to have a size of
# 125Kb, with the first 64Kb of data having the value 0xaa and the second 61Kb
# of data having the value 0x00.
$XFS_IO_PROG -c "truncate 64K" \
		-c "truncate 125K" \
		-c "fsync" \
		$SCRATCH_MNT/foo

# Do something similar to our file bar, but the first truncation sets the file
# size to 0 and the second truncation expands the size to the double of what it
# was initially.
$XFS_IO_PROG -c "truncate 0" \
		-c "truncate 253K" \
		-c "fsync" \
		$SCRATCH_MNT/bar

_flakey_drop_and_remount

# We expect foo to have a size of 125Kb, the first 64Kb of data all having the
# value 0xaa and the remaining 61Kb to be a hole (all bytes with value 0x00).
echo "File foo content after log replay:"
od -t x1 $SCRATCH_MNT/foo

# We expect bar to have a size of 253Kb and no extents (any byte read from bar
# has the value 0x00).
echo "File bar content after log replay:"
od -t x1 $SCRATCH_MNT/bar

status=0
exit
