1#!/usr/bin/env bash 2# 3# Test qcow2 image compression 4# 5# Copyright (C) 2018 Igalia, S.L. 6# Author: Alberto Garcia <berto@igalia.com> 7# 8# This program is free software; you can redistribute it and/or modify 9# it under the terms of the GNU General Public License as published by 10# the Free Software Foundation; either version 2 of the License, or 11# (at your option) any later version. 12# 13# This program is distributed in the hope that it will be useful, 14# but WITHOUT ANY WARRANTY; without even the implied warranty of 15# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 16# GNU General Public License for more details. 17# 18# You should have received a copy of the GNU General Public License 19# along with this program. If not, see <http://www.gnu.org/licenses/>. 20# 21 22seq=$(basename "$0") 23echo "QA output created by $seq" 24 25status=1 # failure is the default! 26 27_cleanup() 28{ 29 _cleanup_test_img 30} 31trap "_cleanup; exit \$status" 0 1 2 3 15 32 33# get standard environment, filters and checks 34. ./common.rc 35. ./common.filter 36 37_supported_fmt qcow2 38_supported_proto file 39_supported_os Linux 40 41# Repairing the corrupted image requires qemu-img check to store a 42# refcount up to 3, which requires at least two refcount bits. 43_unsupported_imgopts 'refcount_bits=1[^0-9]' 44 45 46echo 47echo "=== Corrupted size field in compressed cluster descriptor ===" 48echo 49# Create an empty image and fill half of it with compressed data. 50# The L2 entries of the two compressed clusters are located at 51# 0x800000 and 0x800008, their original values are 0x4008000000a00000 52# and 0x4008000000a00802 (5 sectors for compressed data each). 53_make_test_img 8M -o cluster_size=2M 54$QEMU_IO -c "write -c -P 0x11 0 2M" -c "write -c -P 0x11 2M 2M" "$TEST_IMG" \ 55 2>&1 | _filter_qemu_io | _filter_testdir 56 57# Reduce size of compressed data to 4 sectors: this corrupts the image. 58poke_file "$TEST_IMG" $((0x800000)) "\x40\x06" 59$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 60 61# 'qemu-img check' however doesn't see anything wrong because it 62# doesn't try to decompress the data and the refcounts are consistent. 63# TODO: update qemu-img so this can be detected. 64_check_test_img 65 66# Increase size of compressed data to the maximum (8192 sectors). 67# This makes QEMU read more data (8192 sectors instead of 5, host 68# addresses [0xa00000, 0xdfffff]), but the decompression algorithm 69# stops once we have enough to restore the uncompressed cluster, so 70# the rest of the data is ignored. 71poke_file "$TEST_IMG" $((0x800000)) "\x7f\xfe" 72# Do it also for the second compressed cluster (L2 entry at 0x800008). 73# In this case the compressed data would span 3 host clusters 74# (host addresses: [0xa00802, 0xe00801]) 75poke_file "$TEST_IMG" $((0x800008)) "\x7f\xfe" 76 77# Here the image is too small so we're asking QEMU to read beyond the 78# end of the image. 79$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 80# But if we grow the image we won't be reading beyond its end anymore. 81$QEMU_IO -c "write -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 82$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 83 84# The refcount data is however wrong because due to the increased size 85# of the compressed data it now reaches the following host clusters. 86# This can be repaired by qemu-img check by increasing the refcount of 87# those clusters. 88# TODO: update qemu-img to correct the compressed cluster size instead. 89_check_test_img -r all 90$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 91$QEMU_IO -c "read -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 92 93# success, all done 94echo '*** done' 95rm -f $seq.full 96status=0 97