1#!/usr/bin/env bash
2# group: rw auto
3#
4# Test qcow2 image compression
5#
6# Copyright (C) 2018 Igalia, S.L.
7# Author: Alberto Garcia <berto@igalia.com>
8#
9# This program is free software; you can redistribute it and/or modify
10# it under the terms of the GNU General Public License as published by
11# the Free Software Foundation; either version 2 of the License, or
12# (at your option) any later version.
13#
14# This program is distributed in the hope that it will be useful,
15# but WITHOUT ANY WARRANTY; without even the implied warranty of
16# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
17# GNU General Public License for more details.
18#
19# You should have received a copy of the GNU General Public License
20# along with this program.  If not, see <http://www.gnu.org/licenses/>.
21#
22
23seq=$(basename "$0")
24echo "QA output created by $seq"
25
26status=1	# failure is the default!
27
28_cleanup()
29{
30    _cleanup_test_img
31}
32trap "_cleanup; exit \$status" 0 1 2 3 15
33
34# get standard environment, filters and checks
35. ./common.rc
36. ./common.filter
37
38_supported_fmt qcow2
39_supported_proto file fuse
40
41# Repairing the corrupted image requires qemu-img check to store a
42# refcount up to 3, which requires at least two refcount bits.
43# External data files do not support compressed clusters.
44_unsupported_imgopts 'refcount_bits=1[^0-9]' data_file
45
46
47echo
48echo "=== Corrupted size field in compressed cluster descriptor ==="
49echo
50# Create an empty image and fill half of it with compressed data.
51# The L2 entries of the two compressed clusters are located at
52# 0x800000 and 0x800008, their original values are 0x4008000000a00000
53# and 0x4008000000a00802 (5 sectors for compressed data each).
54_make_test_img 8M -o cluster_size=2M
55$QEMU_IO -c "write -c -P 0x11 0 2M" -c "write -c -P 0x11 2M 2M" "$TEST_IMG" \
56         2>&1 | _filter_qemu_io | _filter_testdir
57
58# Reduce size of compressed data to 4 sectors: this corrupts the image.
59poke_file "$TEST_IMG" $((0x800000)) "\x40\x06"
60$QEMU_IO -c "read  -P 0x11 0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
61
62# 'qemu-img check' however doesn't see anything wrong because it
63# doesn't try to decompress the data and the refcounts are consistent.
64# TODO: update qemu-img so this can be detected.
65_check_test_img
66
67# Increase size of compressed data to the maximum (8192 sectors).
68# This makes QEMU read more data (8192 sectors instead of 5, host
69# addresses [0xa00000, 0xdfffff]), but the decompression algorithm
70# stops once we have enough to restore the uncompressed cluster, so
71# the rest of the data is ignored.
72poke_file "$TEST_IMG" $((0x800000)) "\x7f\xfe"
73# Do it also for the second compressed cluster (L2 entry at 0x800008).
74# In this case the compressed data would span 3 host clusters
75# (host addresses: [0xa00802, 0xe00801])
76poke_file "$TEST_IMG" $((0x800008)) "\x7f\xfe"
77
78# Here the image is too small so we're asking QEMU to read beyond the
79# end of the image.
80$QEMU_IO -c "read  -P 0x11  0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
81# But if we grow the image we won't be reading beyond its end anymore.
82$QEMU_IO -c "write -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
83$QEMU_IO -c "read  -P 0x11  0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
84
85# The refcount data is however wrong because due to the increased size
86# of the compressed data it now reaches the following host clusters.
87# This can be repaired by qemu-img check by increasing the refcount of
88# those clusters.
89# TODO: update qemu-img to correct the compressed cluster size instead.
90_check_test_img -r all
91$QEMU_IO -c "read  -P 0x11  0 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
92$QEMU_IO -c "read  -P 0x22 4M 4M" "$TEST_IMG" 2>&1 | _filter_qemu_io | _filter_testdir
93
94echo
95echo "=== Write compressed data of multiple clusters ==="
96echo
97cluster_size=0x10000
98_make_test_img 2M -o cluster_size=$cluster_size
99
100echo "Write uncompressed data:"
101let data_size="8 * $cluster_size"
102$QEMU_IO -c "write -P 0xaa 0 $data_size" "$TEST_IMG" \
103         2>&1 | _filter_qemu_io | _filter_testdir
104sizeA=$($QEMU_IMG info --output=json "$TEST_IMG" |
105        sed -n '/"actual-size":/ s/[^0-9]//gp')
106
107_make_test_img 2M -o cluster_size=$cluster_size
108echo "Write compressed data:"
109let data_size="3 * $cluster_size + $cluster_size / 2"
110# Set compress on. That will align the written data
111# by the cluster size and will write them compressed.
112QEMU_IO_OPTIONS=$QEMU_IO_OPTIONS_NO_FMT \
113$QEMU_IO -c "write -P 0xbb 0 $data_size" --image-opts \
114         "driver=compress,file.driver=$IMGFMT,file.file.driver=file,file.file.filename=$TEST_IMG" \
115         2>&1 | _filter_qemu_io | _filter_testdir
116
117let offset="4 * $cluster_size + $cluster_size / 4"
118QEMU_IO_OPTIONS=$QEMU_IO_OPTIONS_NO_FMT \
119$QEMU_IO -c "write -P 0xcc $offset $data_size" "json:{\
120    'driver': 'compress',
121    'file': {'driver': '$IMGFMT',
122             'file': {'driver': 'file',
123                      'filename': '$TEST_IMG'}}}" | \
124                          _filter_qemu_io | _filter_testdir
125
126sizeB=$($QEMU_IMG info --output=json "$TEST_IMG" |
127        sed -n '/"actual-size":/ s/[^0-9]//gp')
128
129if [ $sizeA -lt $sizeB ]
130then
131    echo "Compression ERROR ($sizeA < $sizeB)"
132fi
133
134$QEMU_IMG check --output=json "$TEST_IMG" |
135          sed -n 's/,$//; /"compressed-clusters":/ s/^ *//p'
136
137# success, all done
138echo '*** done'
139rm -f $seq.full
140status=0
141