qemu/tests/qemu-iotests/155
Kevin Wolf 8bdee9f10e iotests: Test mirror with temporarily disabled target backing file
The newly tested scenario is a common live storage migration scenario:
The target node is opened without a backing file so that the active
layer is mirrored while its backing chain can be copied in the
background.

The backing chain should be attached to the mirror target node when
finalising the job, just before switching the users of the source node
to the new copy (at which point the mirror job still has a reference to
the node). drive-mirror did this automatically, but with blockdev-mirror
this is the job of the QMP client.

This patch adds test cases for two ways to achieve the desired result,
using either x-blockdev-reopen or blockdev-snapshot.

Signed-off-by: Kevin Wolf <kwolf@redhat.com>
Message-Id: <20200310113831.27293-5-kwolf@redhat.com>
Reviewed-by: Peter Krempa <pkrempa@redhat.com>
Signed-off-by: Kevin Wolf <kwolf@redhat.com>
2020-03-11 15:54:38 +01:00

304 lines
11 KiB
Python
Executable File

#!/usr/bin/env python3
#
# Test whether the backing BDSs are correct after completion of a
# mirror block job; in "existing" modes (drive-mirror with
# mode=existing and blockdev-mirror) the backing chain should not be
# overridden.
#
# Copyright (C) 2016 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/>.
#
import os
import iotests
from iotests import qemu_img
back0_img = os.path.join(iotests.test_dir, 'back0.' + iotests.imgfmt)
back1_img = os.path.join(iotests.test_dir, 'back1.' + iotests.imgfmt)
back2_img = os.path.join(iotests.test_dir, 'back2.' + iotests.imgfmt)
source_img = os.path.join(iotests.test_dir, 'source.' + iotests.imgfmt)
target_img = os.path.join(iotests.test_dir, 'target.' + iotests.imgfmt)
# Class variables for controlling its behavior:
#
# existing: If True, explicitly create the target image and blockdev-add it
# target_backing: If existing is True: Use this filename as the backing file
# of the target image
# (None: no backing file)
# target_blockdev_backing: If existing is True: Pass this dict as "backing"
# for the blockdev-add command
# (None: do not pass "backing")
# target_real_backing: If existing is True: The real filename of the backing
# image during runtime, only makes sense if
# target_blockdev_backing is not None
# (None: same as target_backing)
# target_open_with_backing: If True, the target image is added with its backing
# chain opened right away. If False, blockdev-add
# opens it without a backing file and job completion
# is supposed to open the backing chain.
class BaseClass(iotests.QMPTestCase):
target_blockdev_backing = None
target_real_backing = None
target_open_with_backing = True
def setUp(self):
qemu_img('create', '-f', iotests.imgfmt, back0_img, '1440K')
qemu_img('create', '-f', iotests.imgfmt, '-b', back0_img, back1_img)
qemu_img('create', '-f', iotests.imgfmt, '-b', back1_img, back2_img)
qemu_img('create', '-f', iotests.imgfmt, '-b', back2_img, source_img)
self.vm = iotests.VM()
# Add the BDS via blockdev-add so it stays around after the mirror block
# job has been completed
blockdev = {'node-name': 'source',
'driver': iotests.imgfmt,
'file': {'driver': 'file',
'filename': source_img}}
self.vm.add_blockdev(self.vm.qmp_to_opts(blockdev))
self.vm.add_device('virtio-blk,id=qdev0,drive=source')
self.vm.launch()
self.assertIntactSourceBackingChain()
if self.existing:
if self.target_backing:
qemu_img('create', '-f', iotests.imgfmt,
'-b', self.target_backing, target_img, '1440K')
else:
qemu_img('create', '-f', iotests.imgfmt, target_img, '1440K')
if self.cmd == 'blockdev-mirror':
options = { 'node-name': 'target',
'driver': iotests.imgfmt,
'file': { 'driver': 'file',
'node-name': 'target-file',
'filename': target_img } }
if not self.target_open_with_backing:
options['backing'] = None
elif self.target_blockdev_backing:
options['backing'] = self.target_blockdev_backing
result = self.vm.qmp('blockdev-add', **options)
self.assert_qmp(result, 'return', {})
def tearDown(self):
self.vm.shutdown()
os.remove(source_img)
os.remove(back2_img)
os.remove(back1_img)
os.remove(back0_img)
try:
os.remove(target_img)
except OSError:
pass
def findBlockNode(self, node_name, qdev=None):
if qdev:
result = self.vm.qmp('query-block')
for device in result['return']:
if device['qdev'] == qdev:
if node_name:
self.assert_qmp(device, 'inserted/node-name', node_name)
return device['inserted']
else:
result = self.vm.qmp('query-named-block-nodes')
for node in result['return']:
if node['node-name'] == node_name:
return node
self.fail('Cannot find node %s/%s' % (qdev, node_name))
def assertIntactSourceBackingChain(self):
node = self.findBlockNode('source')
self.assert_qmp(node, 'image' + '/backing-image' * 0 + '/filename',
source_img)
self.assert_qmp(node, 'image' + '/backing-image' * 1 + '/filename',
back2_img)
self.assert_qmp(node, 'image' + '/backing-image' * 2 + '/filename',
back1_img)
self.assert_qmp(node, 'image' + '/backing-image' * 3 + '/filename',
back0_img)
self.assert_qmp_absent(node, 'image' + '/backing-image' * 4)
def assertCorrectBackingImage(self, node, default_image):
if self.existing:
if self.target_real_backing:
image = self.target_real_backing
else:
image = self.target_backing
else:
image = default_image
if image:
self.assert_qmp(node, 'image/backing-image/filename', image)
else:
self.assert_qmp_absent(node, 'image/backing-image')
# Class variables for controlling its behavior:
#
# cmd: Mirroring command to execute, either drive-mirror or blockdev-mirror
class MirrorBaseClass(BaseClass):
def openBacking(self):
pass
def runMirror(self, sync):
if self.cmd == 'blockdev-mirror':
result = self.vm.qmp(self.cmd, job_id='mirror-job', device='source',
sync=sync, target='target',
auto_finalize=False)
else:
if self.existing:
mode = 'existing'
else:
mode = 'absolute-paths'
result = self.vm.qmp(self.cmd, job_id='mirror-job', device='source',
sync=sync, target=target_img,
format=iotests.imgfmt, mode=mode,
node_name='target', auto_finalize=False)
self.assert_qmp(result, 'return', {})
self.vm.run_job('mirror-job', use_log=False, auto_finalize=False,
pre_finalize=self.openBacking, auto_dismiss=True)
def testFull(self):
self.runMirror('full')
node = self.findBlockNode('target',
'/machine/peripheral/qdev0/virtio-backend')
self.assertCorrectBackingImage(node, None)
self.assertIntactSourceBackingChain()
def testTop(self):
self.runMirror('top')
node = self.findBlockNode('target',
'/machine/peripheral/qdev0/virtio-backend')
self.assertCorrectBackingImage(node, back2_img)
self.assertIntactSourceBackingChain()
def testNone(self):
self.runMirror('none')
node = self.findBlockNode('target',
'/machine/peripheral/qdev0/virtio-backend')
self.assertCorrectBackingImage(node, source_img)
self.assertIntactSourceBackingChain()
class TestDriveMirrorAbsolutePaths(MirrorBaseClass):
cmd = 'drive-mirror'
existing = False
class TestDriveMirrorExistingNoBacking(MirrorBaseClass):
cmd = 'drive-mirror'
existing = True
target_backing = None
class TestDriveMirrorExistingBacking(MirrorBaseClass):
cmd = 'drive-mirror'
existing = True
target_backing = 'null-co://'
class TestBlockdevMirrorNoBacking(MirrorBaseClass):
cmd = 'blockdev-mirror'
existing = True
target_backing = None
class TestBlockdevMirrorBacking(MirrorBaseClass):
cmd = 'blockdev-mirror'
existing = True
target_backing = 'null-co://'
class TestBlockdevMirrorForcedBacking(MirrorBaseClass):
cmd = 'blockdev-mirror'
existing = True
target_backing = None
target_blockdev_backing = { 'driver': 'null-co' }
target_real_backing = 'null-co://'
# Attach the backing chain only during completion, with blockdev-reopen
class TestBlockdevMirrorReopen(MirrorBaseClass):
cmd = 'blockdev-mirror'
existing = True
target_backing = 'null-co://'
target_open_with_backing = False
def openBacking(self):
if not self.target_open_with_backing:
result = self.vm.qmp('blockdev-add', node_name="backing",
driver="null-co")
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('x-blockdev-reopen', node_name="target",
driver=iotests.imgfmt, file="target-file",
backing="backing")
self.assert_qmp(result, 'return', {})
# Attach the backing chain only during completion, with blockdev-snapshot
class TestBlockdevMirrorSnapshot(MirrorBaseClass):
cmd = 'blockdev-mirror'
existing = True
target_backing = 'null-co://'
target_open_with_backing = False
def openBacking(self):
if not self.target_open_with_backing:
result = self.vm.qmp('blockdev-add', node_name="backing",
driver="null-co")
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('blockdev-snapshot', node="backing",
overlay="target")
self.assert_qmp(result, 'return', {})
class TestCommit(BaseClass):
existing = False
def testCommit(self):
result = self.vm.qmp('block-commit', job_id='commit-job',
device='source', base=back1_img)
self.assert_qmp(result, 'return', {})
self.vm.event_wait('BLOCK_JOB_READY')
result = self.vm.qmp('block-job-complete', device='commit-job')
self.assert_qmp(result, 'return', {})
self.vm.event_wait('BLOCK_JOB_COMPLETED')
node = self.findBlockNode(None,
'/machine/peripheral/qdev0/virtio-backend')
self.assert_qmp(node, 'image' + '/backing-image' * 0 + '/filename',
back1_img)
self.assert_qmp(node, 'image' + '/backing-image' * 1 + '/filename',
back0_img)
self.assert_qmp_absent(node, 'image' + '/backing-image' * 2 +
'/filename')
self.assertIntactSourceBackingChain()
BaseClass = None
MirrorBaseClass = None
if __name__ == '__main__':
iotests.main(supported_fmts=['qcow2'],
supported_protocols=['file'])