2 # SPDX-License-Identifier: GPL-2.0
3 # Copyright (c) 2017 Facebook. All Rights Reserved.
7 # Test decompression in the middle of large extents. Regression test for Linux
8 # kernel commit 6e78b3f7a193 ("Btrfs: fix btrfs_decompress_buf2page()").
11 _begin_fstest auto compress
13 # Import common functions.
16 # real QA test starts here
20 _require_btrfs_command property
22 algos=($(_btrfs_compression_algos))
24 _scratch_mkfs >>$seqres.full 2>&1
26 # Need 1GB for the uncompressed file plus <1GB for each compressed file.
27 _require_fs_space $SCRATCH_MNT $((1024 * 1024 * (1 + ${#algos[@]})))
29 # Checksum a piece in the middle of the file. This hits the unaligned case that
30 # caused the original bug.
33 dd if="$1" bs=4K skip=555 count=100 2>>$seqres.full| md5sum | cut -d ' ' -f 1
36 # Create a large, uncompressed (but compressible) file.
37 touch "${SCRATCH_MNT}/uncompressed"
38 $BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/uncompressed" compression ""
39 _ddt of="${SCRATCH_MNT}/uncompressed" bs=1M count=1K 2>&1 | _filter_dd
41 csum="$(do_csum "${SCRATCH_MNT}/uncompressed")"
43 for algo in ${algos[@]}; do
44 echo "Testing ${algo}" >> $seqres.full
46 # Copy the same data, but with compression enabled.
47 touch "${SCRATCH_MNT}/${algo}"
48 $BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/${algo}" compression "${algo}"
49 dd if="${SCRATCH_MNT}/uncompressed" of="${SCRATCH_MNT}/${algo}" bs=1M 2>&1 | _filter_dd
51 # The correct data is likely still cached. Cycle the mount to drop the
52 # cache and start fresh.
56 compressed_csum="$(do_csum "${SCRATCH_MNT}/${algo}")"
57 if [ "${compressed_csum}" != "${csum}" ]; then
58 echo "Checksum mismatch for ${algo} (expected ${csum}, got ${compressed_csum})"
62 echo "Silence is golden"