qemu/tests/qemu-iotests/283

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#!/usr/bin/env python3
# group: auto quick
#
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
# Test for copy-before-write filter permission conflict
#
# Copyright (c) 2019 Virtuozzo International GmbH.
#
# 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 iotests
# The test is unrelated to formats, restrict it to qcow2 to avoid extra runs
iotests.script_initialize(
supported_fmts=['qcow2'],
)
size = 1024 * 1024
""" Test description
When performing a backup, all writes on the source subtree must go through the
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
copy-before-write filter so it can copy all data to the target before it is
changed. copy-before-write filter is appended above source node, to achieve
this thing, so all parents of source node are handled. A configuration with
side parents of source sub-tree with write permission is unsupported (we'd have
append several copy-before-write filter like nodes to handle such parents). The
test create an example of such configuration and checks that a backup is then
not allowed (blockdev-backup command should fail).
The configuration:
┌────────┐ target ┌─────────────┐
│ target │ ◀─────── │ backup_top │
└────────┘ └─────────────┘
│ backing
┌─────────────┐
│ source │
└─────────────┘
│ file
┌─────────────┐ write perm ┌───────┐
│ base │ ◀──────────── │ other │
└─────────────┘ └───────┘
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
copy-before-write filter wants to unshare write permission on its source child.
Write unsharing will be propagated to the "source->base" link and will conflict
with other node write permission. So permission update will fail and backup job
will not be started.
Note, that the only thing which prevents backup of running on such
configuration is default permission propagation scheme. It may be altered by
different block drivers, so backup will run in invalid configuration. But
something is better than nothing. Also, before the previous commit (commit
preceding this test creation), starting backup on such configuration led to
crash, so current "something" is a lot better, and this test actual goal is
to check that crash is fixed :)
"""
vm = iotests.VM()
vm.launch()
vm.qmp_log('blockdev-add', **{
'node-name': 'target',
'driver': 'null-co',
'size': size,
})
vm.qmp_log('blockdev-add', **{
'node-name': 'source',
'driver': 'blkdebug',
'image': {'node-name': 'base', 'driver': 'null-co', 'size': size}
})
vm.qmp_log('blockdev-add', **{
'node-name': 'other',
'driver': 'blkdebug',
'image': 'base',
'take-child-perms': ['write']
})
vm.qmp_log('blockdev-backup', sync='full', device='source', target='target')
vm.shutdown()
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
print('\n=== copy-before-write filter should be gone after job-finalize ===\n')
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
# Check that the copy-before-write node is gone after job-finalize.
vm = iotests.VM()
vm.launch()
vm.qmp_log('blockdev-add', **{
'node-name': 'source',
'driver': 'null-co',
})
vm.qmp_log('blockdev-add', **{
'node-name': 'target',
'driver': 'null-co',
})
vm.qmp_log('blockdev-backup',
job_id='backup',
device='source',
target='target',
sync='full',
filter_node_name='backup-filter',
auto_finalize=False,
auto_dismiss=False)
vm.event_wait('BLOCK_JOB_PENDING', 5.0)
block: rename backup-top to copy-before-write We are going to convert backup_top to full featured public filter, which can be used in separate of backup job. Start from renaming from "how it used" to "what it does". While updating comments in 283 iotest, drop and rephrase also things about ".active", as this field is now dropped, and filter doesn't have "inactive" mode. Note that this change may be considered as incompatible interface change, as backup-top filter format name was visible through query-block and query-named-block-nodes. Still, consider the following reasoning: 1. backup-top was never documented, so if someone depends on format name (for driver that can't be used other than it is automatically inserted on backup job start), it's a kind of "undocumented feature use". So I think we are free to change it. 2. There is a hope, that there is no such users: it's a lot more native to give a good node-name to backup-top filter if need to operate with it somehow, and don't touch format name. 3. Another "incompatible" change in further commit would be moving copy-before-write filter from using backing child to file child. And this is even more reasonable than renaming: for now all public filters are file-child based. So, it's a risky change, but risk seems small and good interface worth it. Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com> Reviewed-by: Max Reitz <mreitz@redhat.com> Message-Id: <20210824083856.17408-6-vsementsov@virtuozzo.com> Signed-off-by: Hanna Reitz <hreitz@redhat.com>
2021-08-24 11:38:27 +03:00
# The copy-before-write filter should still be present prior to finalization
assert vm.node_info('backup-filter') is not None
vm.qmp_log('job-finalize', id='backup')
vm.event_wait('BLOCK_JOB_COMPLETED', 5.0)
# The filter should be gone now. Check that by trying to access it
# with qemu-io (which will most likely crash qemu if it is still
# there.).
vm.qmp_log('human-monitor-command',
command_line='qemu-io backup-filter "write 0 1M"')
# (Also, do an explicit check.)
assert vm.node_info('backup-filter') is None
vm.qmp_log('job-dismiss', id='backup')
vm.event_wait('JOB_STATUS_CHANGE', 5.0, {'data': {'status': 'null'}})
vm.shutdown()