#! /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.
#
. ./common/preamble
_begin_fstest auto quick dedupe clone

# Import common functions.
. ./common/filter
. ./common/reflink

# real QA test starts here
_supported_fs generic
_require_scratch_dedupe

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

# The first byte with a value of 0xae starts at an offset (512Kb + 100) which is
# not a multiple of the block size.
$XFS_IO_PROG -f \
	-c "pwrite -S 0x6b 0 524388" \
	-c "pwrite -S 0xae 524388 256K" \
	$SCRATCH_MNT/foo | _filter_xfs_io

# Create a second file with a length not aligned to the block size (128K + 100),
# 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 131172" $SCRATCH_MNT/bar | _filter_xfs_io

# The file is filled with bytes having the value 0x6b from offset 0 to offset
# 524388 (512K + 100) and with the value 0xae from offset 524388 to offset
# 786532 (512K + 100 + 256K).
echo "File content before first deduplication:"
od -A d -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 524388).
$XFS_IO_PROG -c "dedupe $SCRATCH_MNT/bar 0 64K 131172" $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. The destination range,
# in file foo, has all bytes with the same value (0xae) as file baz.
$XFS_IO_PROG -c "dedupe $SCRATCH_MNT/baz 0 640K 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