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.env 39. ./common.rc 40. ./common.filter 41 42# This tests qocw2-specific low-level functionality 43_supported_fmt qcow2 44_supported_proto file 45_supported_os Linux 46 47rt_offset=65536 # 0x10000 (XXX: just an assumption) 48rb_offset=131072 # 0x20000 (XXX: just an assumption) 49l1_offset=196608 # 0x30000 (XXX: just an assumption) 50l2_offset=262144 # 0x40000 (XXX: just an assumption) 51l2_offset_after_snapshot=524288 # 0x80000 (XXX: just an assumption) 52 53IMGOPTS="compat=1.1" 54 55OPEN_RW="open -o overlap-check=all $TEST_IMG" 56# Overlap checks are done before write operations only, therefore opening an 57# image read-only makes the overlap-check option irrelevant 58OPEN_RO="open -r $TEST_IMG" 59 60echo 61echo "=== Testing L2 reference into L1 ===" 62echo 63_make_test_img 64M 64# Link first L1 entry (first L2 table) onto itself 65# (Note the MSb in the L1 entry is set, ensuring the refcount is one - else any 66# later write will result in a COW operation, effectively ruining this attempt 67# on image corruption) 68poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x03\x00\x00" 69_check_test_img 70 71# The corrupt bit should not be set anyway 72$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 73 74# Try to write something, thereby forcing the corrupt bit to be set 75$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 76 77# The corrupt bit must now be set 78$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 79 80# Try to open the image R/W (which should fail) 81$QEMU_IO -c "$OPEN_RW" -c "read 0 512" 2>&1 | _filter_qemu_io \ 82 | _filter_testdir \ 83 | _filter_imgfmt 84 85# Try to open it RO (which should succeed) 86$QEMU_IO -c "$OPEN_RO" -c "read 0 512" | _filter_qemu_io 87 88# We could now try to fix the image, but this would probably fail (how should an 89# L2 table linked onto the L1 table be fixed?) 90 91echo 92echo "=== Testing cluster data reference into refcount block ===" 93echo 94_make_test_img 64M 95# Allocate L2 table 96truncate -s "$(($l2_offset+65536))" "$TEST_IMG" 97poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x04\x00\x00" 98# Mark cluster as used 99poke_file "$TEST_IMG" "$(($rb_offset+8))" "\x00\x01" 100# Redirect new data cluster onto refcount block 101poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x02\x00\x00" 102_check_test_img 103$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 104$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 105$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 106 107# Try to fix it 108_check_test_img -r all 109 110# The corrupt bit should be cleared 111$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 112 113# Look if it's really really fixed 114$QEMU_IO -c "$OPEN_RW" -c "write -P 0x2a 0 512" | _filter_qemu_io 115$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 116 117echo 118echo "=== Testing cluster data reference into inactive L2 table ===" 119echo 120_make_test_img 64M 121$QEMU_IO -c "$OPEN_RW" -c "write -P 1 0 512" | _filter_qemu_io 122$QEMU_IMG snapshot -c foo "$TEST_IMG" 123$QEMU_IO -c "$OPEN_RW" -c "write -P 2 0 512" | _filter_qemu_io 124# The inactive L2 table remains at its old offset 125poke_file "$TEST_IMG" "$l2_offset_after_snapshot" \ 126 "\x80\x00\x00\x00\x00\x04\x00\x00" 127_check_test_img 128$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 129$QEMU_IO -c "$OPEN_RW" -c "write -P 3 0 512" | _filter_qemu_io 130$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 131_check_test_img -r all 132$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 133$QEMU_IO -c "$OPEN_RW" -c "write -P 4 0 512" | _filter_qemu_io 134$PYTHON qcow2.py "$TEST_IMG" dump-header | grep incompatible_features 135 136# Check data 137$QEMU_IO -c "$OPEN_RO" -c "read -P 4 0 512" | _filter_qemu_io 138$QEMU_IMG snapshot -a foo "$TEST_IMG" 139_check_test_img 140$QEMU_IO -c "$OPEN_RO" -c "read -P 1 0 512" | _filter_qemu_io 141 142echo 143echo "=== Testing overlap while COW is in flight ===" 144echo 145# compat=0.10 is required in order to make the following discard actually 146# unallocate the sector rather than make it a zero sector - we want COW, after 147# all. 148IMGOPTS='compat=0.10' _make_test_img 1G 149# Write two clusters, the second one enforces creation of an L2 table after 150# the first data cluster. 151$QEMU_IO -c 'write 0k 64k' -c 'write 512M 64k' "$TEST_IMG" | _filter_qemu_io 152# Discard the first cluster. This cluster will soon enough be reallocated and 153# used for COW. 154$QEMU_IO -c 'discard 0k 64k' "$TEST_IMG" | _filter_qemu_io 155# Now, corrupt the image by marking the second L2 table cluster as free. 156poke_file "$TEST_IMG" '131084' "\x00\x00" # 0x2000c 157# Start a write operation requiring COW on the image stopping it right before 158# doing the read; then, trigger the corruption prevention by writing anything to 159# any unallocated cluster, leading to an attempt to overwrite the second L2 160# table. Finally, resume the COW write and see it fail (but not crash). 161echo "open -o file.driver=blkdebug $TEST_IMG 162break cow_read 0 163aio_write 0k 1k 164wait_break 0 165write 64k 64k 166resume 0" | $QEMU_IO | _filter_qemu_io 167 168# success, all done 169echo "*** done" 170rm -f $seq.full 171status=0 172