qemu-iotests: Overlapping cluster allocations

#!/bin/bash

#

# Test case for image corruption (overlapping data structures) in qcow2

#

# Copyright (C) 2013 Red Hat, Inc.

#

# This program is free software; you can redistribute it and/or modify

# it under the terms of the GNU General Public License as published by

# the Free Software Foundation; either version 2 of the License, or

# (at your option) any later version.

#

# This program is distributed in the hope that it will be useful,

# but WITHOUT ANY WARRANTY; without even the implied warranty of

# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

# GNU General Public License for more details.

#

# You should have received a copy of the GNU General Public License

# along with this program.  If not, see <http://www.gnu.org/licenses/>.

#

# creator

owner=mreitz@redhat.com

seq=`basename $0`

echo "QA output created by $seq"

here=`pwd`

tmp=/tmp/$$

status=1	# failure is the default!

_cleanup()

{

	_cleanup_test_img

}

trap "_cleanup; exit \$status" 0 1 2 3 15

# get standard environment, filters and checks

. ./common.rc

. ./common.filter

# This tests qocw2-specific low-level functionality

_supported_fmt qcow2

_supported_proto generic

_supported_os Linux

rt_offset=65536  # 0x10000 (XXX: just an assumption)

rb_offset=131072 # 0x20000 (XXX: just an assumption)

l1_offset=196608 # 0x30000 (XXX: just an assumption)

l2_offset=262144 # 0x40000 (XXX: just an assumption)

IMGOPTS="compat=1.1"

echo

echo "=== Testing L2 reference into L1 ==="

echo

_make_test_img 64M

# Link first L1 entry (first L2 table) onto itself

# (Note the MSb in the L1 entry is set, ensuring the refcount is one - else any

# later write will result in a COW operation, effectively ruining this attempt

# on image corruption)

poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x03\x00\x00"

_check_test_img

# The corrupt bit should not be set anyway

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

# Try to write something, thereby forcing the corrupt bit to be set

$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io

# The corrupt bit must now be set

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

# Try to open the image R/W (which should fail)

$QEMU_IO -c "read 0 512" "$TEST_IMG" 2>&1 | _filter_qemu_io | sed -e "s/can't open device .*$/can't open device/"

# Try to open it RO (which should succeed)

$QEMU_IO -c "read 0 512" -r "$TEST_IMG" | _filter_qemu_io

# We could now try to fix the image, but this would probably fail (how should an

# L2 table linked onto the L1 table be fixed?)

echo

echo "=== Testing cluster data reference into refcount block ==="

echo

_make_test_img 64M

# Allocate L2 table

truncate -s "$(($l2_offset+65536))" "$TEST_IMG"

poke_file "$TEST_IMG" "$l1_offset" "\x80\x00\x00\x00\x00\x04\x00\x00"

# Mark cluster as used

poke_file "$TEST_IMG" "$(($rb_offset+8))" "\x00\x01"

# Redirect new data cluster onto refcount block

poke_file "$TEST_IMG" "$l2_offset" "\x80\x00\x00\x00\x00\x02\x00\x00"

_check_test_img

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

# Try to fix it

_check_test_img -r all

# The corrupt bit should be cleared

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

# Look if it's really really fixed

$QEMU_IO -c "write -P 0x2a 0 512" "$TEST_IMG" | _filter_qemu_io

./qcow2.py "$TEST_IMG" dump-header | grep incompatible_features

# success, all done

echo "*** done"

rm -f $seq.full

status=0

QA output created by 060

=== Testing L2 reference into L1 ===

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 

ERROR cluster 3 refcount=1 reference=3

1 errors were found on the image.

Data may be corrupted, or further writes to the image may corrupt it.

incompatible_features     0x0

qcow2: Preventing invalid write on metadata (overlaps with active L1 table); image marked as corrupt.

write failed: Input/output error

incompatible_features     0x2

qcow2: Image is corrupt; cannot be opened read/write.

qemu-io: can't open device

no file open, try 'help open'

read 512/512 bytes at offset 0

512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

=== Testing cluster data reference into refcount block ===

Formatting 'TEST_DIR/t.IMGFMT', fmt=IMGFMT size=67108864 

ERROR refcount block 0 refcount=2

ERROR cluster 2 refcount=1 reference=2

2 errors were found on the image.

Data may be corrupted, or further writes to the image may corrupt it.

incompatible_features     0x0

qcow2: Preventing invalid write on metadata (overlaps with refcount block); image marked as corrupt.

write failed: Input/output error

incompatible_features     0x2

Repairing refcount block 0 refcount=2

The following inconsistencies were found and repaired:

    0 leaked clusters

    1 corruptions

Double checking the fixed image now...

No errors were found on the image.

incompatible_features     0x0

wrote 512/512 bytes at offset 0

512 bytes, X ops; XX:XX:XX.X (XXX YYY/sec and XXX ops/sec)

incompatible_features     0x0

*** done

055 rw auto

056 rw auto backing

059 rw auto

060 rw auto

062 rw auto