qemu/tests/qemu-iotests/224

#!/usr/bin/env python3
#
# Test json:{} filenames with qemu-internal BDSs
# (the one of commit, to be precise)
#
# Copyright (C) 2018 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: Max Reitz <mreitz@redhat.com>

import iotests
from iotests import log, qemu_img, qemu_io_silent, filter_qmp_testfiles, \
                    filter_qmp_imgfmt
import json

# Need backing file support (for arbitrary backing formats)
iotests.script_initialize(supported_fmts=['qcow2', 'qcow', 'qed'],
                          supported_platforms=['linux'])


# There are two variations of this test:
# (1) We do not set filter_node_name.  In that case, the commit_top
#     driver should not appear anywhere.
# (2) We do set filter_node_name.  In that case, it should appear.
#
# This for loop executes both.
for filter_node_name in False, True:
    log('')
    log('--- filter_node_name: %s ---' % filter_node_name)
    log('')

    with iotests.FilePath('base.img') as base_img_path, \
         iotests.FilePath('mid.img') as mid_img_path, \
         iotests.FilePath('top.img') as top_img_path, \
         iotests.VM() as vm:

        assert qemu_img('create', '-f', iotests.imgfmt,
                        base_img_path, '64M') == 0
        assert qemu_img('create', '-f', iotests.imgfmt, '-b', base_img_path,
                        '-F', iotests.imgfmt, mid_img_path) == 0
        assert qemu_img('create', '-f', iotests.imgfmt, '-b', mid_img_path,
                        '-F', iotests.imgfmt, top_img_path) == 0

        # Something to commit
        assert qemu_io_silent(mid_img_path, '-c', 'write -P 1 0 1M') == 0

        vm.launch()

        # Change the bottom-most image's backing file (to null-co://)
        # to enforce json:{} filenames
        vm.qmp_log('blockdev-add',
                    node_name='top',
                    driver=iotests.imgfmt,
                    file={
                        'driver': 'file',
                        'filename': top_img_path
                    },
                    backing={
                        'node-name': 'mid',
                        'driver': iotests.imgfmt,
                        'file': {
                            'driver': 'file',
                            'filename': mid_img_path
                        },
                        'backing': {
                            'node-name': 'base',
                            'driver': iotests.imgfmt,
                            'file': {
                                'driver': 'file',
                                'filename': base_img_path
                            },
                            'backing': {
                                'driver': 'null-co'
                            }
                        }
                    },
                    filters=[filter_qmp_testfiles, filter_qmp_imgfmt])

        # As long as block-commit does not accept node names, we have to
        # get our mid/base filenames here
        mid_name = vm.node_info('mid')['image']['filename']
        base_name = vm.node_info('base')['image']['filename']

        assert mid_name[:5] == 'json:'
        assert base_name[:5] == 'json:'

        # Start the block job
        if filter_node_name:
            vm.qmp_log('block-commit',
                        job_id='commit',
                        device='top',
                        filter_node_name='filter_node',
                        top=mid_name,
                        base=base_name,
                        speed=1,
                        filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
        else:
            vm.qmp_log('block-commit',
                        job_id='commit',
                        device='top',
                        top=mid_name,
                        base=base_name,
                        speed=1,
                        filters=[filter_qmp_testfiles, filter_qmp_imgfmt])

        vm.qmp_log('job-pause', id='commit')

        # Get and parse top's json:{} filename
        top_name = vm.node_info('top')['image']['filename']

        vm.shutdown()

        assert top_name[:5] == 'json:'
        top_options = json.loads(top_name[5:])

        if filter_node_name:
            # This should be present and set
            assert top_options['backing']['driver'] == 'commit_top'
            # And the mid image is commit_top's backing image
            mid_options = top_options['backing']['backing']
        else:
            # The mid image should appear as the immediate backing BDS
            # of top
            mid_options = top_options['backing']

        assert mid_options['driver'] == iotests.imgfmt
        assert mid_options['file']['filename'] == mid_img_path