iotests: Add test for backing file overrides

Signed-off-by: Max Reitz <mreitz@redhat.com>
Message-id: 20190201192935.18394-9-mreitz@redhat.com
Signed-off-by: Max Reitz <mreitz@redhat.com>
This commit is contained in:
Max Reitz 2019-02-01 20:29:12 +01:00
parent ef7afd6399
commit 0f62cd8204
3 changed files with 327 additions and 0 deletions

242
tests/qemu-iotests/228 Executable file
View File

@ -0,0 +1,242 @@
#!/usr/bin/env python
#
# Test for when a backing file is considered overridden (thus, a
# json:{} filename is generated for the overlay) and when it is not
#
# 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, filter_testfiles, filter_imgfmt, \
filter_qmp_testfiles, filter_qmp_imgfmt
# Need backing file and change-backing-file support
iotests.verify_image_format(supported_fmts=['qcow2', 'qed'])
iotests.verify_platform(['linux'])
def log_node_info(node):
log('')
log('bs->filename: ' + node['image']['filename'],
filters=[filter_testfiles, filter_imgfmt])
log('bs->backing_file: ' + node['backing_file'],
filters=[filter_testfiles, filter_imgfmt])
if 'backing-image' in node['image']:
log('bs->backing->bs->filename: ' +
node['image']['backing-image']['filename'],
filters=[filter_testfiles, filter_imgfmt])
else:
log('bs->backing: (none)')
log('')
with iotests.FilePath('base.img') as base_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
# Choose a funny way to describe the backing filename
assert qemu_img('create', '-f', iotests.imgfmt, '-b',
'file:' + base_img_path, top_img_path) == 0
vm.launch()
log('--- Implicit backing file ---')
log('')
vm.qmp_log('blockdev-add',
node_name='node0',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': top_img_path
},
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
# Filename should be plain, and the backing filename should not
# contain the "file:" prefix
log_node_info(vm.node_info('node0'))
vm.qmp_log('blockdev-del', node_name='node0')
log('')
log('--- change-backing-file ---')
log('')
vm.qmp_log('blockdev-add',
node_name='node0',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': top_img_path
},
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
# Changing the backing file to a qemu-reported filename should
# result in qemu accepting the corresponding BDS as the implicit
# backing BDS (and thus not generate a json:{} filename).
# So, first, query the backing filename.
backing_filename = \
vm.node_info('node0')['image']['backing-image']['filename']
# Next, change the backing file to something different
vm.qmp_log('change-backing-file',
image_node_name='node0',
device='node0',
backing_file='null-co://',
filters=[filter_qmp_testfiles])
# Now, verify that we get a json:{} filename
# (Image header says "null-co://", actual backing file still is
# base_img_path)
log_node_info(vm.node_info('node0'))
# Change it back
# (To get header and backing file in sync)
vm.qmp_log('change-backing-file',
image_node_name='node0',
device='node0',
backing_file=backing_filename,
filters=[filter_qmp_testfiles])
# And verify that we get our original results
log_node_info(vm.node_info('node0'))
# Finally, try a "file:" prefix. While this is actually what we
# originally had in the image header, qemu will not reopen the
# backing file here, so it cannot verify that this filename
# "resolves" to the actual backing BDS's filename and will thus
# consider both to be different.
# (This may be fixed in the future.)
vm.qmp_log('change-backing-file',
image_node_name='node0',
device='node0',
backing_file=('file:' + backing_filename),
filters=[filter_qmp_testfiles])
# So now we should get a json:{} filename
log_node_info(vm.node_info('node0'))
# Remove and re-attach so we can see that (as in our first try),
# opening the image anew helps qemu resolve the header backing
# filename.
vm.qmp_log('blockdev-del', node_name='node0')
vm.qmp_log('blockdev-add',
node_name='node0',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': top_img_path
},
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
log_node_info(vm.node_info('node0'))
vm.qmp_log('blockdev-del', node_name='node0')
log('')
log('--- Override backing file ---')
log('')
# For this test, we need the plain filename in the image header
# (because qemu cannot "canonicalize"/"resolve" the backing
# filename unless the backing file is opened implicitly with the
# overlay)
assert qemu_img('create', '-f', iotests.imgfmt, '-b', base_img_path,
top_img_path) == 0
# You can only reliably override backing options by using a node
# reference (or by specifying file.filename, but, well...)
vm.qmp_log('blockdev-add', node_name='null', driver='null-co')
vm.qmp_log('blockdev-add',
node_name='node0',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': top_img_path
},
backing='null',
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
# Should get a json:{} filename (and bs->backing_file is
# null-co://, because that field actually has not much to do
# with the header backing filename (except that it is changed by
# change-backing-file))
log_node_info(vm.node_info('node0'))
# Detach the backing file by reopening the whole thing
vm.qmp_log('blockdev-del', node_name='node0')
vm.qmp_log('blockdev-del', node_name='null')
vm.qmp_log('blockdev-add',
node_name='node0',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': top_img_path
},
backing=None,
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
# Should get a json:{} filename (because we overrode the backing
# file to not be there)
log_node_info(vm.node_info('node0'))
# Open the original backing file
vm.qmp_log('blockdev-add',
node_name='original-backing',
driver=iotests.imgfmt,
file={
'driver': 'file',
'filename': base_img_path
},
filters=[filter_qmp_testfiles, filter_qmp_imgfmt])
# Attach the original backing file to its overlay
vm.qmp_log('blockdev-snapshot',
node='original-backing',
overlay='node0')
# This should give us the original plain result
# FIXME: Currently, the block layer considers the runtime backing
# file to be different from the image header, which is
# wrong. This is fixed by a future patch.
log_node_info(vm.node_info('node0'))
vm.qmp_log('blockdev-del', node_name='node0')
vm.qmp_log('blockdev-del', node_name='original-backing')
vm.shutdown()

View File

@ -0,0 +1,84 @@
--- Implicit backing file ---
{"execute": "blockdev-add", "arguments": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}, "node-name": "node0"}}
{"return": {}}
bs->filename: TEST_DIR/PID-top.img
bs->backing_file: TEST_DIR/PID-base.img
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "blockdev-del", "arguments": {"node-name": "node0"}}
{"return": {}}
--- change-backing-file ---
{"execute": "blockdev-add", "arguments": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}, "node-name": "node0"}}
{"return": {}}
{"execute": "change-backing-file", "arguments": {"backing-file": "null-co://", "device": "node0", "image-node-name": "node0"}}
{"return": {}}
bs->filename: json:{"backing": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-base.img"}}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}}
bs->backing_file: null-co://
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "change-backing-file", "arguments": {"backing-file": "TEST_DIR/PID-base.img", "device": "node0", "image-node-name": "node0"}}
{"return": {}}
bs->filename: TEST_DIR/PID-top.img
bs->backing_file: TEST_DIR/PID-base.img
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "change-backing-file", "arguments": {"backing-file": "file:TEST_DIR/PID-base.img", "device": "node0", "image-node-name": "node0"}}
{"return": {}}
bs->filename: json:{"backing": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-base.img"}}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}}
bs->backing_file: file:TEST_DIR/PID-base.img
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "blockdev-del", "arguments": {"node-name": "node0"}}
{"return": {}}
{"execute": "blockdev-add", "arguments": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}, "node-name": "node0"}}
{"return": {}}
bs->filename: TEST_DIR/PID-top.img
bs->backing_file: TEST_DIR/PID-base.img
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "blockdev-del", "arguments": {"node-name": "node0"}}
{"return": {}}
--- Override backing file ---
{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "null"}}
{"return": {}}
{"execute": "blockdev-add", "arguments": {"backing": "null", "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}, "node-name": "node0"}}
{"return": {}}
bs->filename: json:{"backing": {"driver": "null-co"}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}}
bs->backing_file: null-co://
bs->backing->bs->filename: null-co://
{"execute": "blockdev-del", "arguments": {"node-name": "node0"}}
{"return": {}}
{"execute": "blockdev-del", "arguments": {"node-name": "null"}}
{"return": {}}
{"execute": "blockdev-add", "arguments": {"backing": null, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}, "node-name": "node0"}}
{"return": {}}
bs->filename: json:{"backing": null, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}}
bs->backing_file: TEST_DIR/PID-base.img
bs->backing: (none)
{"execute": "blockdev-add", "arguments": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-base.img"}, "node-name": "original-backing"}}
{"return": {}}
{"execute": "blockdev-snapshot", "arguments": {"node": "original-backing", "overlay": "node0"}}
{"return": {}}
bs->filename: json:{"backing": {"driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-base.img"}}, "driver": "IMGFMT", "file": {"driver": "file", "filename": "TEST_DIR/PID-top.img"}}
bs->backing_file: TEST_DIR/PID-base.img
bs->backing->bs->filename: TEST_DIR/PID-base.img
{"execute": "blockdev-del", "arguments": {"node-name": "node0"}}
{"return": {}}
{"execute": "blockdev-del", "arguments": {"node-name": "original-backing"}}
{"return": {}}

View File

@ -227,6 +227,7 @@
225 rw auto quick 225 rw auto quick
226 auto quick 226 auto quick
227 auto quick 227 auto quick
228 rw auto quick
229 auto quick 229 auto quick
231 auto quick 231 auto quick
232 auto quick 232 auto quick