#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2019 SUSE Linux Products GmbH. All Rights Reserved.
#
# FSQA Test No. 183
#
# Regression test for read corruption of compressed and shared extents after
# punching holes into a file.
#
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()
{
	cd /
	rm -f $tmp.*
}

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

# real QA test starts here
_supported_fs btrfs
_require_scratch_reflink
_require_xfs_io_command "fpunch"

rm -f $seqres.full

_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount "-o compress"

# Create a file with 3 consecutive compressed extents, each corresponds to 128Kb
# of data (uncompressed size) and each is stored on disk as a 4Kb extent
# (compressed size, regardless of compression algorithm used).
# Each extent starts with 4Kb of zeroes, while the remaining bytes all have a
# value of 0xff.
$XFS_IO_PROG -f -c "pwrite -S 0xff 0 384K" \
	     -c "pwrite -S 0x00 0 4K" \
	     -c "pwrite -S 0x00 128K 4K" \
	     -c "pwrite -S 0x00 256K 4K" \
	     $SCRATCH_MNT/foobar | _filter_xfs_io

echo "File digest after initial creation:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch

# Clone the first extent into offsets 128K and 256K.
$XFS_IO_PROG -c "reflink $SCRATCH_MNT/foobar 0 128K 128K" \
	     -c "reflink $SCRATCH_MNT/foobar 0 256K 128K" \
	     $SCRATCH_MNT/foobar | _filter_xfs_io

echo "File digest after reflinking:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch

# Punch holes into the regions that are already full of zeroes.
$XFS_IO_PROG -c "fpunch 0 4K" \
	     -c "fpunch 128K 4K" \
	     -c "fpunch 256K 4K" \
	     $SCRATCH_MNT/foobar

echo "File digest after punching holes:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch

echo 1 > /proc/sys/vm/drop_caches

echo "File digest after dropping page cache:"
md5sum $SCRATCH_MNT/foobar | _filter_scratch

status=0
exit