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 $seq" 24 25status=1 # failure is the default! 26 27_cleanup() 28{ 29 _cleanup_test_img 30} 31trap "_cleanup; exit \$status" 0 1 2 3 15 32 33# get standard environment, filters and checks 34. ./common.rc 35. ./common.filter 36 37_supported_fmt qcow2 38_supported_proto file 39 40# Repairing the corrupted image requires qemu-img check to store a 41# refcount up to 3, which requires at least two refcount bits. 42_unsupported_imgopts 'refcount_bits=1[^0-9]' 43 44 45echo 46echo "=== Corrupted size field in compressed cluster descriptor ===" 47echo 48# Create an empty image and fill half of it with compressed data. 49# The L2 entries of the two compressed clusters are located at 50# 0x800000 and 0x800008, their original values are 0x4008000000a00000 51# and 0x4008000000a00802 (5 sectors for compressed data each). 52_make_test_img 8M -o cluster_size=2M 53$QEMU_IO -c "write -c -P 0x11 0 2M" -c "write -c -P 0x11 2M 2M" "$TEST_IMG" \ 54 2>&1 | _filter_qemu_io | _filter_testdir 55 56# Reduce size of compressed data to 4 sectors: this corrupts the image. 57poke_file "$TEST_IMG" $((0x800000)) "\x40\x06" 58$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 59 60# 'qemu-img check' however doesn't see anything wrong because it 61# doesn't try to decompress the data and the refcounts are consistent. 62# TODO: update qemu-img so this can be detected. 63_check_test_img 64 65# Increase size of compressed data to the maximum (8192 sectors). 66# This makes QEMU read more data (8192 sectors instead of 5, host 67# addresses [0xa00000, 0xdfffff]), but the decompression algorithm 68# stops once we have enough to restore the uncompressed cluster, so 69# the rest of the data is ignored. 70poke_file "$TEST_IMG" $((0x800000)) "\x7f\xfe" 71# Do it also for the second compressed cluster (L2 entry at 0x800008). 72# In this case the compressed data would span 3 host clusters 73# (host addresses: [0xa00802, 0xe00801]) 74poke_file "$TEST_IMG" $((0x800008)) "\x7f\xfe" 75 76# Here the image is too small so we're asking QEMU to read beyond the 77# end of the image. 78$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 79# But if we grow the image we won't be reading beyond its end anymore. 80$QEMU_IO -c "write -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 81$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 82 83# The refcount data is however wrong because due to the increased size 84# of the compressed data it now reaches the following host clusters. 85# This can be repaired by qemu-img check by increasing the refcount of 86# those clusters. 87# TODO: update qemu-img to correct the compressed cluster size instead. 88_check_test_img -r all 89$QEMU_IO -c "read -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 90$QEMU_IO -c "read -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir 91 92# success, all done 93echo '*** done' 94rm -f $seq.full 95status=0 96