qemu/tests/qemu-iotests/108

#!/usr/bin/env bash
#
# Test case for repairing qcow2 images which cannot be repaired using
# the on-disk refcount structures
#
# Copyright (C) 2014 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"

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 qcow2-specific low-level functionality
_supported_fmt qcow2
_supported_proto file fuse
_supported_os Linux
# This test directly modifies a refblock so it relies on refcount_bits being 16;
# and the low-level modification it performs are not tuned for external data
# files
_unsupported_imgopts 'refcount_bits=\([^1]\|.\([^6]\|$\)\)' data_file

echo
echo '=== Repairing an image without any refcount table ==='
echo

_make_test_img 64M
# just write some data
$QEMU_IO -c 'write -P 42 0 64k' "$TEST_IMG" | _filter_qemu_io

# refcount_table_offset
poke_file "$TEST_IMG" $((0x30)) "\x00\x00\x00\x00\x00\x00\x00\x00"
# refcount_table_clusters
poke_file "$TEST_IMG" $((0x38)) "\x00\x00\x00\x00"

_check_test_img -r all

$QEMU_IO -c 'read -P 42 0 64k' "$TEST_IMG" | _filter_qemu_io

echo
echo '=== Repairing unreferenced data cluster in new refblock area ==='
echo

_make_test_img -o 'cluster_size=512' 64M
# Allocate the first 128 kB in the image (first refblock)
$QEMU_IO -c 'write 0 0x1b200' "$TEST_IMG" | _filter_qemu_io
# should be 131072 == 0x20000
stat -c '%s' "$TEST_IMG"

# Enter a cluster at 128 kB (0x20000)
# XXX: This should be the first free entry in the last L2 table, but we cannot
# be certain
poke_file "$TEST_IMG" $((0x1ccc8)) "\x80\x00\x00\x00\x00\x02\x00\x00"

# Fill the cluster
truncate -s $((0x20200)) "$TEST_IMG"
$QEMU_IO -c "open -o driver=raw $TEST_IMG" -c 'write -P 42 128k 512' \
    | _filter_qemu_io

# The data should now appear at this guest offset
$QEMU_IO -c 'read -P 42 0x1b200 512' "$TEST_IMG" | _filter_qemu_io

# This cluster is unallocated; fix it
_check_test_img -r all

# This repair operation must have allocated a new refblock; and that refblock
# should not overlap with the unallocated data cluster. If it does, the data
# will be damaged, so check it.
$QEMU_IO -c 'read -P 42 0x1b200 512' "$TEST_IMG" | _filter_qemu_io

echo
echo '=== Repairing refblock beyond the image end ==='
echo

echo
echo '--- Otherwise clean ---'
echo

_make_test_img 64M
# Normally, qemu doesn't create empty refblocks, so we just have to do it by
# hand
# XXX: This should be the entry for the second refblock
poke_file "$TEST_IMG" $((0x10008)) "\x00\x00\x00\x00\x00\x10\x00\x00"
# Mark that refblock as used
# XXX: This should be the 17th entry (cluster 16) of the first
# refblock
poke_file "$TEST_IMG" $((0x20020)) "\x00\x01"
_check_test_img -r all

echo
echo '--- Refblock is unallocated ---'
echo

_make_test_img 64M
poke_file "$TEST_IMG" $((0x10008)) "\x00\x00\x00\x00\x00\x10\x00\x00"
_check_test_img -r all

echo
echo '--- Signed overflow after the refblock ---'
echo

_make_test_img 64M
poke_file "$TEST_IMG" $((0x10008)) "\x7f\xff\xff\xff\xff\xff\x00\x00"
_check_test_img -r all

echo
echo '--- Unsigned overflow after the refblock ---'
echo

_make_test_img 64M
poke_file "$TEST_IMG" $((0x10008)) "\xff\xff\xff\xff\xff\xff\x00\x00"
_check_test_img -r all

# success, all done
echo '*** done'
rm -f $seq.full
status=0