qemu/tests/qemu-iotests/139
Markus Armbruster c42e8742f5 block: Use JSON null instead of "" to disable backing file
BlockdevRef is an alternate of BlockdevOptions (inline definition) and
str (reference to an existing block device by name).  BlockdevRef
value "" is special: "no block device should be referenced."  It's
actually interpreted that way in just one place: optional member
@backing of COW formats.  Semantics:

* Present means "use this block device" as backing storage

* Absent means "default to the one stored in the image"

* Except "" means "don't use backing storage at all"

The first two are perfectly normal: when the parameter is absent, it
defaults to an implied value, but the value's meaning is the same.

The third one overloads the parameter with a second meaning.  The
overloading is *implicit*, i.e. it's not visible in the types.  Works
here, because "" is not a value block device ID.

Pressing argument values the schema accepts, but are semantically
invalid, into service to mean "do something else entirely" is not
general, as suitable invalid values need not exist.  I also find it
ugly.

To clean this up, we could add a separate flag argument to suppress
@backing, or add a distinct value to @backing.  This commit implements
the latter: add JSON null to the values of @backing, deprecate "".

Because we're so close to the 2.10 freeze, implement it in the
stupidest way possible: have qmp_blockdev_add() rewrite null to ""
before anything else can see the null.  Works, because BlockdevRef
occurs only within arguments of blockdev-add.  The proper way to do it
would be rewriting "" to null, preferably in a cleaner way, but that
requires fixing up code to work with null.  Add a TODO comment for
that.

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrange <berrange@redhat.com>
Acked-by: Kevin Wolf <kwolf@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
2017-07-24 13:35:11 +02:00

354 lines
15 KiB
Python

#!/usr/bin/env python
#
# Test cases for the QMP 'blockdev-del' command
#
# Copyright (C) 2015 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/>.
#
import os
import iotests
import time
base_img = os.path.join(iotests.test_dir, 'base.img')
new_img = os.path.join(iotests.test_dir, 'new.img')
class TestBlockdevDel(iotests.QMPTestCase):
def setUp(self):
iotests.qemu_img('create', '-f', iotests.imgfmt, base_img, '1M')
self.vm = iotests.VM()
self.vm.add_device("virtio-scsi-pci,id=virtio-scsi")
self.vm.launch()
def tearDown(self):
self.vm.shutdown()
os.remove(base_img)
if os.path.isfile(new_img):
os.remove(new_img)
# Check whether a BlockDriverState exists
def checkBlockDriverState(self, node, must_exist = True):
result = self.vm.qmp('query-named-block-nodes')
nodes = filter(lambda x: x['node-name'] == node, result['return'])
self.assertLessEqual(len(nodes), 1)
self.assertEqual(must_exist, len(nodes) == 1)
# Add a BlockDriverState without a BlockBackend
def addBlockDriverState(self, node):
file_node = '%s_file' % node
self.checkBlockDriverState(node, False)
self.checkBlockDriverState(file_node, False)
opts = {'driver': iotests.imgfmt,
'node-name': node,
'file': {'driver': 'file',
'node-name': file_node,
'filename': base_img}}
result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
self.checkBlockDriverState(file_node)
# Add a BlockDriverState that will be used as overlay for the base_img BDS
def addBlockDriverStateOverlay(self, node):
self.checkBlockDriverState(node, False)
iotests.qemu_img('create', '-u', '-f', iotests.imgfmt,
'-b', base_img, new_img, '1M')
opts = {'driver': iotests.imgfmt,
'node-name': node,
'backing': None,
'file': {'driver': 'file',
'filename': new_img}}
result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
# Delete a BlockDriverState
def delBlockDriverState(self, node, expect_error = False):
self.checkBlockDriverState(node)
result = self.vm.qmp('blockdev-del', node_name = node)
if expect_error:
self.assert_qmp(result, 'error/class', 'GenericError')
else:
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node, expect_error)
# Add a device model
def addDeviceModel(self, device, backend, driver = 'virtio-blk-pci'):
result = self.vm.qmp('device_add', id = device,
driver = driver, drive = backend)
self.assert_qmp(result, 'return', {})
# Delete a device model
def delDeviceModel(self, device, is_virtio_blk = True):
result = self.vm.qmp('device_del', id = device)
self.assert_qmp(result, 'return', {})
result = self.vm.qmp('system_reset')
self.assert_qmp(result, 'return', {})
if is_virtio_blk:
device_path = '/machine/peripheral/%s/virtio-backend' % device
event = self.vm.event_wait(name="DEVICE_DELETED",
match={'data': {'path': device_path}})
self.assertNotEqual(event, None)
event = self.vm.event_wait(name="DEVICE_DELETED",
match={'data': {'device': device}})
self.assertNotEqual(event, None)
# Remove a BlockDriverState
def ejectDrive(self, device, node, expect_error = False,
destroys_media = True):
self.checkBlockDriverState(node)
result = self.vm.qmp('eject', id = device)
if expect_error:
self.assert_qmp(result, 'error/class', 'GenericError')
self.checkBlockDriverState(node)
else:
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node, not destroys_media)
# Insert a BlockDriverState
def insertDrive(self, device, node):
self.checkBlockDriverState(node)
result = self.vm.qmp('x-blockdev-insert-medium',
id = device, node_name = node)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
# Create a snapshot using 'blockdev-snapshot-sync'
def createSnapshotSync(self, node, overlay):
self.checkBlockDriverState(node)
self.checkBlockDriverState(overlay, False)
opts = {'node-name': node,
'snapshot-file': new_img,
'snapshot-node-name': overlay,
'format': iotests.imgfmt}
result = self.vm.qmp('blockdev-snapshot-sync', conv_keys=False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
self.checkBlockDriverState(overlay)
# Create a snapshot using 'blockdev-snapshot'
def createSnapshot(self, node, overlay):
self.checkBlockDriverState(node)
self.checkBlockDriverState(overlay)
result = self.vm.qmp('blockdev-snapshot',
node = node, overlay = overlay)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
self.checkBlockDriverState(overlay)
# Create a mirror
def createMirror(self, node, new_node):
self.checkBlockDriverState(new_node, False)
opts = {'device': node,
'job-id': node,
'target': new_img,
'node-name': new_node,
'sync': 'top',
'format': iotests.imgfmt}
result = self.vm.qmp('drive-mirror', conv_keys=False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(new_node)
# Complete an existing block job
def completeBlockJob(self, id, node_before, node_after):
result = self.vm.qmp('block-job-complete', device=id)
self.assert_qmp(result, 'return', {})
self.wait_until_completed(id)
# Add a BlkDebug node
# Note that the purpose of this is to test the blockdev-del
# sanity checks, not to create a usable blkdebug drive
def addBlkDebug(self, debug, node):
self.checkBlockDriverState(node, False)
self.checkBlockDriverState(debug, False)
image = {'driver': iotests.imgfmt,
'node-name': node,
'file': {'driver': 'file',
'filename': base_img}}
opts = {'driver': 'blkdebug',
'node-name': debug,
'image': image}
result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(node)
self.checkBlockDriverState(debug)
# Add a BlkVerify node
# Note that the purpose of this is to test the blockdev-del
# sanity checks, not to create a usable blkverify drive
def addBlkVerify(self, blkverify, test, raw):
self.checkBlockDriverState(test, False)
self.checkBlockDriverState(raw, False)
self.checkBlockDriverState(blkverify, False)
iotests.qemu_img('create', '-f', iotests.imgfmt, new_img, '1M')
node_0 = {'driver': iotests.imgfmt,
'node-name': test,
'file': {'driver': 'file',
'filename': base_img}}
node_1 = {'driver': iotests.imgfmt,
'node-name': raw,
'file': {'driver': 'file',
'filename': new_img}}
opts = {'driver': 'blkverify',
'node-name': blkverify,
'test': node_0,
'raw': node_1}
result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(test)
self.checkBlockDriverState(raw)
self.checkBlockDriverState(blkverify)
# Add a Quorum node
def addQuorum(self, quorum, child0, child1):
self.checkBlockDriverState(child0, False)
self.checkBlockDriverState(child1, False)
self.checkBlockDriverState(quorum, False)
iotests.qemu_img('create', '-f', iotests.imgfmt, new_img, '1M')
child_0 = {'driver': iotests.imgfmt,
'node-name': child0,
'file': {'driver': 'file',
'filename': base_img}}
child_1 = {'driver': iotests.imgfmt,
'node-name': child1,
'file': {'driver': 'file',
'filename': new_img}}
opts = {'driver': 'quorum',
'node-name': quorum,
'vote-threshold': 1,
'children': [ child_0, child_1 ]}
result = self.vm.qmp('blockdev-add', conv_keys = False, **opts)
self.assert_qmp(result, 'return', {})
self.checkBlockDriverState(child0)
self.checkBlockDriverState(child1)
self.checkBlockDriverState(quorum)
########################
# The tests start here #
########################
def testBlockDriverState(self):
self.addBlockDriverState('node0')
# You cannot delete a file BDS directly
self.delBlockDriverState('node0_file', expect_error = True)
self.delBlockDriverState('node0')
def testDeviceModel(self):
self.addBlockDriverState('node0')
self.addDeviceModel('device0', 'node0')
self.ejectDrive('device0', 'node0', expect_error = True)
self.delBlockDriverState('node0', expect_error = True)
self.delDeviceModel('device0')
self.delBlockDriverState('node0')
def testAttachMedia(self):
# This creates a BlockBackend and removes its media
self.addBlockDriverState('node0')
self.addDeviceModel('device0', 'node0', 'scsi-cd')
self.ejectDrive('device0', 'node0', destroys_media = False)
self.delBlockDriverState('node0')
# This creates a new BlockDriverState and inserts it into the device
self.addBlockDriverState('node1')
self.insertDrive('device0', 'node1')
# The node can't be removed: the new device has an extra reference
self.delBlockDriverState('node1', expect_error = True)
# The BDS still exists after being ejected, but now it can be removed
self.ejectDrive('device0', 'node1', destroys_media = False)
self.delBlockDriverState('node1')
self.delDeviceModel('device0', False)
def testSnapshotSync(self):
self.addBlockDriverState('node0')
self.addDeviceModel('device0', 'node0')
self.createSnapshotSync('node0', 'overlay0')
# This fails because node0 is now being used as a backing image
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('overlay0', expect_error = True)
# This succeeds because device0 only has the backend reference
self.delDeviceModel('device0')
# FIXME Would still be there if blockdev-snapshot-sync took a ref
self.checkBlockDriverState('overlay0', False)
self.delBlockDriverState('node0')
def testSnapshot(self):
self.addBlockDriverState('node0')
self.addDeviceModel('device0', 'node0', 'scsi-cd')
self.addBlockDriverStateOverlay('overlay0')
self.createSnapshot('node0', 'overlay0')
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('overlay0', expect_error = True)
self.ejectDrive('device0', 'overlay0', destroys_media = False)
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('overlay0')
self.delBlockDriverState('node0')
def testMirror(self):
self.addBlockDriverState('node0')
self.addDeviceModel('device0', 'node0', 'scsi-cd')
self.createMirror('node0', 'mirror0')
# The block job prevents removing the device
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('mirror0', expect_error = True)
self.wait_ready('node0')
self.completeBlockJob('node0', 'node0', 'mirror0')
self.assert_no_active_block_jobs()
# This succeeds because the device now points to mirror0
self.delBlockDriverState('node0')
self.delBlockDriverState('mirror0', expect_error = True)
self.delDeviceModel('device0', False)
# FIXME mirror0 disappears, drive-mirror doesn't take a reference
#self.delBlockDriverState('mirror0')
def testBlkDebug(self):
self.addBlkDebug('debug0', 'node0')
# 'node0' is used by the blkdebug node
self.delBlockDriverState('node0', expect_error = True)
# But we can remove the blkdebug node directly
self.delBlockDriverState('debug0')
self.checkBlockDriverState('node0', False)
def testBlkVerify(self):
self.addBlkVerify('verify0', 'node0', 'node1')
# We cannot remove the children of a blkverify device
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('node1', expect_error = True)
# But we can remove the blkverify node directly
self.delBlockDriverState('verify0')
self.checkBlockDriverState('node0', False)
self.checkBlockDriverState('node1', False)
def testQuorum(self):
if not iotests.supports_quorum():
return
self.addQuorum('quorum0', 'node0', 'node1')
# We cannot remove the children of a Quorum device
self.delBlockDriverState('node0', expect_error = True)
self.delBlockDriverState('node1', expect_error = True)
# But we can remove the Quorum node directly
self.delBlockDriverState('quorum0')
self.checkBlockDriverState('node0', False)
self.checkBlockDriverState('node1', False)
if __name__ == '__main__':
iotests.main(supported_fmts=["qcow2"])