1#!/bin/bash 2# 3# Test case for image corruption (overlapping data structures) in qcow2 4# 5# Copyright (C) 2013 Red Hat, Inc. 6# 7# This program is free software; you can redistribute it and/or modify 8# it under the terms of the GNU General Public License as published by 9# the Free Software Foundation; either version 2 of the License, or 10# (at your option) any later version. 11# 12# This program is distributed in the hope that it will be useful, 13# but WITHOUT ANY WARRANTY; without even the implied warranty of 14# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15# GNU General Public License for more details. 16# 17# You should have received a copy of the GNU General Public License 18# along with this program. If not, see <http://www.gnu.org/licenses/>. 19# 20 21# creator 22owner=mreitz@redhat.com 23 24seq="$(basename $0)" 25echo "QA output created by $seq" 26 27here="$PWD" 28tmp=/tmp/$$ 29status=1 # failure is the default! 30 31_cleanup() 32{ 33 _cleanup_test_img 34} 35trap "_cleanup; exit \$status" 0 1 2 3 15 36 37# get standard environment, filters and checks 38. ./common.rc 39. ./common.filter 40 41# This tests qocw2-specific low-level functionality 42_supported_fmt qcow2 43_supported_proto file 44_supported_os Linux 45 46rt_offset=65536 # 0x10000 (XXX: just an assumption) 47rb_offset=131072 # 0x20000 (XXX: just an assumption) 48l1_offset=196608 # 0x30000 (XXX: just an assumption) 49l2_offset=262144 # 0x40000 (XXX: just an assumption) 50l2_offset_after_snapshot=524288 # 0x80000 (XXX: just an assumption) 51 52IMGOPTS="compat=1.1" 53 54OPEN_RW="open -o overlap-check=all $TEST_IMG" 55# Overlap checks are done before write operations only, therefore opening an 56# image read-only makes the overlap-check option irrelevant 57OPEN_RO="open -r $TEST_IMG" 58 59echo 60echo "=== Testing L2 reference into L1 ===" 61echo 62_make_test_img 64M 63# Link first L1 entry (first L2 table) onto itself 64# (Note the MSb in the L1 entry is set, ensuring the refcount is one - else any 65# later write will result in a COW operation, effectively ruining this attempt 66# on image corruption) 67poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x03\x00\x00" 68_check_test_img 69 70# The corrupt bit should not be set anyway 71./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 72 73# Try to write something, thereby forcing the corrupt bit to be set 74$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 75 76# The corrupt bit must now be set 77./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 78 79# Try to open the image R/W (which should fail) 80$QEMU_IO -c "$OPEN_RW" -c "read 0 512" 2>&1 | _filter_qemu_io \ 81 | _filter_testdir \ 82 | _filter_imgfmt 83 84# Try to open it RO (which should succeed) 85$QEMU_IO -c "$OPEN_RO" -c "read 0 512" | _filter_qemu_io 86 87# We could now try to fix the image, but this would probably fail (how should an 88# L2 table linked onto the L1 table be fixed?) 89 90echo 91echo "=== Testing cluster data reference into refcount block ===" 92echo 93_make_test_img 64M 94# Allocate L2 table 95truncate -s "$(($l2_offset+65536))" "$TEST_IMG" 96poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x04\x00\x00" 97# Mark cluster as used 98poke_file "$TEST_IMG" "$(($rb_offset+8))" "\x00\x01" 99# Redirect new data cluster onto refcount block 100poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x02\x00\x00" 101_check_test_img 102./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 103$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 104./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 105 106# Try to fix it 107_check_test_img -r all 108 109# The corrupt bit should be cleared 110./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 111 112# Look if it's really really fixed 113$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 114./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 115 116echo 117echo "=== Testing cluster data reference into inactive L2 table ===" 118echo 119_make_test_img 64M 120$QEMU_IO -c "$OPEN_RW" -c "write -P 1 0 512" | _filter_qemu_io 121$QEMU_IMG snapshot -c foo "$TEST_IMG" 122$QEMU_IO -c "$OPEN_RW" -c "write -P 2 0 512" | _filter_qemu_io 123# The inactive L2 table remains at its old offset 124poke_file "$TEST_IMG" "$l2_offset_after_snapshot" \ 125 "\x80\x00\x00\x00\x00\x04\x00\x00" 126_check_test_img 127./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 128$QEMU_IO -c "$OPEN_RW" -c "write -P 3 0 512" | _filter_qemu_io 129./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 130_check_test_img -r all 131./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 132$QEMU_IO -c "$OPEN_RW" -c "write -P 4 0 512" | _filter_qemu_io 133./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 134 135# Check data 136$QEMU_IO -c "$OPEN_RO" -c "read -P 4 0 512" | _filter_qemu_io 137$QEMU_IMG snapshot -a foo "$TEST_IMG" 138_check_test_img 139$QEMU_IO -c "$OPEN_RO" -c "read -P 1 0 512" | _filter_qemu_io 140 141echo 142echo "=== Testing overlap while COW is in flight ===" 143echo 144# compat=0.10 is required in order to make the following discard actually 145# unallocate the sector rather than make it a zero sector - we want COW, after 146# all. 147IMGOPTS='compat=0.10' _make_test_img 1G 148# Write two clusters, the second one enforces creation of an L2 table after 149# the first data cluster. 150$QEMU_IO -c 'write 0k 64k' -c 'write 512M 64k' "$TEST_IMG" | _filter_qemu_io 151# Discard the first cluster. This cluster will soon enough be reallocated and 152# used for COW. 153$QEMU_IO -c 'discard 0k 64k' "$TEST_IMG" | _filter_qemu_io 154# Now, corrupt the image by marking the second L2 table cluster as free. 155poke_file "$TEST_IMG" '131084' "\x00\x00" # 0x2000c 156# Start a write operation requiring COW on the image stopping it right before 157# doing the read; then, trigger the corruption prevention by writing anything to 158# any unallocated cluster, leading to an attempt to overwrite the second L2 159# table. Finally, resume the COW write and see it fail (but not crash). 160echo "open -o file.driver=blkdebug $TEST_IMG 161break cow_read 0 162aio_write 0k 1k 163wait_break 0 164write 64k 64k 165resume 0" | $QEMU_IO | _filter_qemu_io 166 167# success, all done 168echo "*** done" 169rm -f $seq.full 170status=0 171