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 seqres=$RESULT_DIR/$seq
12 echo "QA output created by $seq"
16 status=1 # failure is the default!
17 trap "_cleanup; exit \$status" 0 1 2 3 15
25 # get standard environment, filters and checks
29 # remove previous $seqres.full before test
32 # real QA test starts here
37 _require_btrfs_command property
39 algos=($(_btrfs_compression_algos))
41 _scratch_mkfs >>$seqres.full 2>&1
43 # Need 1GB for the uncompressed file plus <1GB for each compressed file.
44 _require_fs_space $SCRATCH_MNT $((1024 * 1024 * (1 + ${#algos[@]})))
46 # Checksum a piece in the middle of the file. This hits the unaligned case that
47 # caused the original bug.
50 dd if="$1" bs=4K skip=555 count=100 2>>$seqres.full| md5sum | cut -d ' ' -f 1
53 # Create a large, uncompressed (but compressible) file.
54 touch "${SCRATCH_MNT}/uncompressed"
55 $BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/uncompressed" compression ""
56 _ddt of="${SCRATCH_MNT}/uncompressed" bs=1M count=1K 2>&1 | _filter_dd
58 csum="$(do_csum "${SCRATCH_MNT}/uncompressed")"
60 for algo in ${algos[@]}; do
61 echo "Testing ${algo}" >> $seqres.full
63 # Copy the same data, but with compression enabled.
64 touch "${SCRATCH_MNT}/${algo}"
65 $BTRFS_UTIL_PROG property set "${SCRATCH_MNT}/${algo}" compression "${algo}"
66 dd if="${SCRATCH_MNT}/uncompressed" of="${SCRATCH_MNT}/${algo}" bs=1M 2>&1 | _filter_dd
68 # The correct data is likely still cached. Cycle the mount to drop the
69 # cache and start fresh.
73 compressed_csum="$(do_csum "${SCRATCH_MNT}/${algo}")"
74 if [ "${compressed_csum}" != "${csum}" ]; then
75 echo "Checksum mismatch for ${algo} (expected ${csum}, got ${compressed_csum})"
79 echo "Silence is golden"