apfstests/tests/generic/517

#! /bin/bash
# SPDX-License-Identifier: GPL-2.0
# Copyright (C) 2018 SUSE Linux Products GmbH. All Rights Reserved.
#
# FS QA Test No. 517
#
# Test that deduplication of an entire file that has a size that is not aligned
# to the filesystem's block size into the middle of a different file does not
# corrupt the destination's file data by reflinking the last (eof) block.
#
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 generic
_supported_os Linux
_require_scratch_dedupe

rm -f $seqres.full

_scratch_mkfs >>$seqres.full 2>&1
_scratch_mount

# The first byte with a value of 0xae starts at an offset (2518890) which is not
# a multiple of the block size.
$XFS_IO_PROG -f \
	-c "pwrite -S 0x6b 0 2518890" \
	-c "pwrite -S 0xae 2518890 102398" \
	$SCRATCH_MNT/foo | _filter_xfs_io

# Create a second file with a length not aligned to the block size, whose bytes
# all have the value 0x6b, so that its extent(s) can be deduplicated with the
# first file.
$XFS_IO_PROG -f -c "pwrite -S 0x6b 0 557771" $SCRATCH_MNT/bar | _filter_xfs_io

# The file is filled with bytes having the value 0x6b from offset 0 to offset
# 2518889 and with the value 0xae from offset 2518890 to offset 2621287.
echo "File content before first deduplication:"
od -t x1 $SCRATCH_MNT/foo

# Now deduplicate the entire second file into a range of the first file that
# also has all bytes with the value 0x6b. The destination range's end offset
# must not be aligned to the block size and must be less then the offset of
# the first byte with the value 0xae (byte at offset 2518890).
$XFS_IO_PROG -c "dedupe $SCRATCH_MNT/bar 0 1957888 557771" $SCRATCH_MNT/foo \
	| _filter_xfs_io

# We should have exactly the same data we had before we asked for deduplication.
echo "File content after first deduplication and before unmounting:"
od -A d -t x1 $SCRATCH_MNT/foo

# Unmount the filesystem and mount it again. This guarantees any file data in
# the page cache is dropped.
_scratch_cycle_mount

# We should have exactly the same data we had before we asked for deduplication.
echo "File content after first unmount:"
od -A d -t x1 $SCRATCH_MNT/foo

# Now do a similar test when trying to dedup just the last (eof) block of a file
# into the middle of another file. This triggered a different bug on btrfs.
$XFS_IO_PROG -f -c "pwrite -S 0xae 0 100" $SCRATCH_MNT/baz | _filter_xfs_io

# Unmount the filesystem and mount it again before attempting to dedupe baz's
# last block into foo. This is necessary to trigger that btrfs bug mentioned
# before.
_scratch_cycle_mount

# Now attempt to dedupe the single block of baz into foo.
$XFS_IO_PROG -c "dedupe $SCRATCH_MNT/baz 0 2519040 100" $SCRATCH_MNT/foo \
    | _filter_xfs_io

# Now attempt to unmount the filesystem before reading from the file. This is
# meant to trigger the btrfs bug which caused an infinite loop during inode
# eviction.
_scratch_cycle_mount

# We should have exactly the same data we had before we asked for deduplication.
echo "File content after second deduplication:"
od -A d -t x1 $SCRATCH_MNT/foo

status=0
exit