b66ff2c298
There are many existing qcow2 images that specify a backing file but no format. This has been the source of CVEs in the past, but has become more prominent of a problem now that libvirt has switched to -blockdev. With older -drive, at least the probing was always done by qemu (so the only risk of a changed format between successive boots of a guest was if qemu was upgraded and probed differently). But with newer -blockdev, libvirt must specify a format; if libvirt guesses raw where the image was formatted, this results in data corruption visible to the guest; conversely, if libvirt guesses qcow2 where qemu was using raw, this can result in potential security holes, so modern libvirt instead refuses to use images without explicit backing format. The change in libvirt to reject images without explicit backing format has pointed out that a number of tools have been far too reliant on probing in the past. It's time to set a better example in our own iotests of properly setting this parameter. iotest calls to create, rebase, and convert are all impacted to some degree. It's a bit annoying that we are inconsistent on command line - while all of those accept -o backing_file=...,backing_fmt=..., the shortcuts are different: create and rebase have -b and -F, while convert has -B but no -F. (amend has no shortcuts, but the previous patch just deprecated the use of amend to change backing chains). Signed-off-by: Eric Blake <eblake@redhat.com> Message-Id: <20200706203954.341758-9-eblake@redhat.com> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
98 lines
3.1 KiB
Bash
Executable file
98 lines
3.1 KiB
Bash
Executable file
#!/usr/bin/env bash
|
|
#
|
|
# Test how 'qemu-io -c discard' behaves on v2 and v3 qcow2 images
|
|
#
|
|
# Copyright (C) 2020 Igalia, S.L.
|
|
# Author: Alberto Garcia <berto@igalia.com>
|
|
#
|
|
# 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=berto@igalia.com
|
|
|
|
seq=`basename $0`
|
|
echo "QA output created by $seq"
|
|
|
|
status=1 # failure is the default!
|
|
|
|
_cleanup()
|
|
{
|
|
_cleanup_test_img
|
|
}
|
|
trap "_cleanup; exit \$status" 0 1 2 3 15
|
|
|
|
# get standard environment, filters and checks
|
|
. ./common.rc
|
|
. ./common.filter
|
|
|
|
_supported_fmt qcow2
|
|
_supported_proto file
|
|
_supported_os Linux
|
|
_unsupported_imgopts 'compat=0.10' refcount_bits data_file
|
|
|
|
echo
|
|
echo "### Test 'qemu-io -c discard' on a QCOW2 image without a backing file"
|
|
echo
|
|
for qcow2_compat in 0.10 1.1; do
|
|
echo "# Create an image with compat=$qcow2_compat without a backing file"
|
|
_make_test_img -o "compat=$qcow2_compat" 128k
|
|
|
|
echo "# Fill all clusters with data and then discard them"
|
|
$QEMU_IO -c 'write -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
$QEMU_IO -c 'discard 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
|
|
echo "# Read the data from the discarded clusters"
|
|
$QEMU_IO -c 'read -P 0x00 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
|
|
echo "# Output of qemu-img map"
|
|
$QEMU_IMG map "$TEST_IMG" | _filter_testdir
|
|
done
|
|
|
|
echo
|
|
echo "### Test 'qemu-io -c discard' on a QCOW2 image with a backing file"
|
|
echo
|
|
|
|
echo "# Create a backing image and fill it with data"
|
|
BACKING_IMG="$TEST_IMG.base"
|
|
TEST_IMG="$BACKING_IMG" _make_test_img 128k
|
|
$QEMU_IO -c 'write -P 0xff 0 128k' "$BACKING_IMG" | _filter_qemu_io
|
|
|
|
for qcow2_compat in 0.10 1.1; do
|
|
echo "# Create an image with compat=$qcow2_compat and a backing file"
|
|
_make_test_img -o "compat=$qcow2_compat" -b "$BACKING_IMG" -F $IMGFMT
|
|
|
|
echo "# Fill all clusters with data and then discard them"
|
|
$QEMU_IO -c 'write -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
$QEMU_IO -c 'discard 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
|
|
echo "# Read the data from the discarded clusters"
|
|
if [ "$qcow2_compat" = "1.1" ]; then
|
|
# In qcow2 v3 clusters are zeroed (with QCOW_OFLAG_ZERO)
|
|
$QEMU_IO -c 'read -P 0x00 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
else
|
|
# In qcow2 v2 if there's a backing image we cannot zero the clusters
|
|
# without exposing the backing file data so discard does nothing
|
|
$QEMU_IO -c 'read -P 0x01 0 128k' "$TEST_IMG" | _filter_qemu_io
|
|
fi
|
|
|
|
echo "# Output of qemu-img map"
|
|
$QEMU_IMG map "$TEST_IMG" | _filter_testdir
|
|
done
|
|
|
|
# success, all done
|
|
echo "*** done"
|
|
rm -f $seq.full
|
|
status=0
|