| 1 | #!/usr/bin/env python3 |
| 2 | # group: auto quick |
| 3 | # |
| 4 | # Test for copy-before-write filter permission conflict |
| 5 | # |
| 6 | # Copyright (c) 2019 Virtuozzo International GmbH. |
| 7 | # |
| 8 | # This program is free software; you can redistribute it and/or modify |
| 9 | # it under the terms of the GNU General Public License as published by |
| 10 | # the Free Software Foundation; either version 2 of the License, or |
| 11 | # (at your option) any later version. |
| 12 | # |
| 13 | # This program is distributed in the hope that it will be useful, |
| 14 | # but WITHOUT ANY WARRANTY; without even the implied warranty of |
| 15 | # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| 16 | # GNU General Public License for more details. |
| 17 | # |
| 18 | # You should have received a copy of the GNU General Public License |
| 19 | # along with this program. If not, see <http://www.gnu.org/licenses/>. |
| 20 | # |
| 21 | |
| 22 | import iotests |
| 23 | |
| 24 | # The test is unrelated to formats, restrict it to qcow2 to avoid extra runs |
| 25 | iotests.script_initialize( |
| 26 | supported_fmts=['qcow2'], |
| 27 | require_hmp=True, |
| 28 | ) |
| 29 | |
| 30 | size = 1024 * 1024 |
| 31 | |
| 32 | """ Test description |
| 33 | |
| 34 | When performing a backup, all writes on the source subtree must go through the |
| 35 | copy-before-write filter so it can copy all data to the target before it is |
| 36 | changed. copy-before-write filter is appended above source node, to achieve |
| 37 | this thing, so all parents of source node are handled. A configuration with |
| 38 | side parents of source sub-tree with write permission is unsupported (we'd have |
| 39 | append several copy-before-write filter like nodes to handle such parents). The |
| 40 | test create an example of such configuration and checks that a backup is then |
| 41 | not allowed (blockdev-backup command should fail). |
| 42 | |
| 43 | The configuration: |
| 44 | |
| 45 | ┌────────┐ target ┌─────────────┐ |
| 46 | │ target │ ◀─────── │ backup_top │ |
| 47 | └────────┘ └─────────────┘ |
| 48 | │ |
| 49 | │ backing |
| 50 | ▼ |
| 51 | ┌─────────────┐ |
| 52 | │ source │ |
| 53 | └─────────────┘ |
| 54 | │ |
| 55 | │ file |
| 56 | ▼ |
| 57 | ┌─────────────┐ write perm ┌───────┐ |
| 58 | │ base │ ◀──────────── │ other │ |
| 59 | └─────────────┘ └───────┘ |
| 60 | |
| 61 | copy-before-write filter wants to unshare write permission on its source child. |
| 62 | Write unsharing will be propagated to the "source->base" link and will conflict |
| 63 | with other node write permission. So permission update will fail and backup job |
| 64 | will not be started. |
| 65 | |
| 66 | Note, that the only thing which prevents backup of running on such |
| 67 | configuration is default permission propagation scheme. It may be altered by |
| 68 | different block drivers, so backup will run in invalid configuration. But |
| 69 | something is better than nothing. Also, before the previous commit (commit |
| 70 | preceding this test creation), starting backup on such configuration led to |
| 71 | crash, so current "something" is a lot better, and this test actual goal is |
| 72 | to check that crash is fixed :) |
| 73 | """ |
| 74 | |
| 75 | vm = iotests.VM() |
| 76 | vm.launch() |
| 77 | |
| 78 | vm.qmp_log('blockdev-add', **{ |
| 79 | 'node-name': 'target', |
| 80 | 'driver': 'null-co', |
| 81 | 'size': size, |
| 82 | }) |
| 83 | |
| 84 | vm.qmp_log('blockdev-add', **{ |
| 85 | 'node-name': 'source', |
| 86 | 'driver': 'blkdebug', |
| 87 | 'image': {'node-name': 'base', 'driver': 'null-co', 'size': size} |
| 88 | }) |
| 89 | |
| 90 | vm.qmp_log('blockdev-add', **{ |
| 91 | 'node-name': 'other', |
| 92 | 'driver': 'blkdebug', |
| 93 | 'image': 'base', |
| 94 | 'take-child-perms': ['write'] |
| 95 | }) |
| 96 | |
| 97 | vm.qmp_log('blockdev-backup', sync='full', device='source', target='target', |
| 98 | job_id="backup0") |
| 99 | |
| 100 | vm.shutdown() |
| 101 | |
| 102 | |
| 103 | print('\n=== copy-before-write filter should be gone after job-finalize ===\n') |
| 104 | |
| 105 | # Check that the copy-before-write node is gone after job-finalize. |
| 106 | |
| 107 | vm = iotests.VM() |
| 108 | vm.launch() |
| 109 | |
| 110 | vm.qmp_log('blockdev-add', **{ |
| 111 | 'node-name': 'source', |
| 112 | 'driver': 'null-co', |
| 113 | }) |
| 114 | |
| 115 | vm.qmp_log('blockdev-add', **{ |
| 116 | 'node-name': 'target', |
| 117 | 'driver': 'null-co', |
| 118 | }) |
| 119 | |
| 120 | vm.qmp_log('blockdev-backup', |
| 121 | job_id='backup', |
| 122 | device='source', |
| 123 | target='target', |
| 124 | sync='full', |
| 125 | filter_node_name='backup-filter', |
| 126 | auto_finalize=False, |
| 127 | auto_dismiss=False) |
| 128 | |
| 129 | vm.event_wait('BLOCK_JOB_PENDING', 5.0) |
| 130 | |
| 131 | # The copy-before-write filter should still be present prior to finalization |
| 132 | assert vm.node_info('backup-filter') is not None |
| 133 | |
| 134 | vm.qmp_log('job-finalize', id='backup') |
| 135 | vm.event_wait('BLOCK_JOB_COMPLETED', 5.0) |
| 136 | |
| 137 | # The filter should be gone now. Check that by trying to access it |
| 138 | # with qemu-io (which will most likely crash qemu if it is still |
| 139 | # there.). |
| 140 | vm.qmp_log('human-monitor-command', |
| 141 | command_line='qemu-io backup-filter "write 0 1M"') |
| 142 | |
| 143 | # (Also, do an explicit check.) |
| 144 | assert vm.node_info('backup-filter') is None |
| 145 | |
| 146 | vm.qmp_log('job-dismiss', id='backup') |
| 147 | vm.event_wait('JOB_STATUS_CHANGE', 5.0, {'data': {'status': 'null'}}) |
| 148 | |
| 149 | vm.shutdown() |