From: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
To: qemu-block@nongnu.org
Cc: kwolf@redhat.com, qemu-stable@nongnu.org,
vsementsov@virtuozzo.com, qemu-devel@nongnu.org,
mreitz@redhat.com
Subject: [PATCH v2 2/2] iotests: add test for backup-top failure on permission activation
Date: Tue, 21 Jan 2020 17:28:02 +0300 [thread overview]
Message-ID: <20200121142802.21467-3-vsementsov@virtuozzo.com> (raw)
In-Reply-To: <20200121142802.21467-1-vsementsov@virtuozzo.com>
This test checks that bug is really fixed by previous commit.
Cc: qemu-stable@nongnu.org # v4.2.0
Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
tests/qemu-iotests/283 | 92 ++++++++++++++++++++++++++++++++++++++
tests/qemu-iotests/283.out | 8 ++++
tests/qemu-iotests/group | 1 +
3 files changed, 101 insertions(+)
create mode 100644 tests/qemu-iotests/283
create mode 100644 tests/qemu-iotests/283.out
diff --git a/tests/qemu-iotests/283 b/tests/qemu-iotests/283
new file mode 100644
index 0000000000..293e557bd9
--- /dev/null
+++ b/tests/qemu-iotests/283
@@ -0,0 +1,92 @@
+#!/usr/bin/env python
+#
+# Test for backup-top filter permission activation failure
+#
+# 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.verify_image_format(supported_fmts=['qcow2'])
+
+size = 1024 * 1024
+
+""" Test description
+
+When performing a backup, all writes on the source subtree must go through the
+backup-top filter so it can copy all data to the target before it is changed.
+backup-top 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
+backup-top 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 │
+ └─────────────┘ └───────┘
+
+On activation (see .active field of backup-top state in block/backup-top.c),
+backup-top is going 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'})
+
+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()
diff --git a/tests/qemu-iotests/283.out b/tests/qemu-iotests/283.out
new file mode 100644
index 0000000000..daaf5828c1
--- /dev/null
+++ b/tests/qemu-iotests/283.out
@@ -0,0 +1,8 @@
+{"execute": "blockdev-add", "arguments": {"driver": "null-co", "node-name": "target"}}
+{"return": {}}
+{"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": {"driver": "null-co", "node-name": "base", "size": 1048576}, "node-name": "source"}}
+{"return": {}}
+{"execute": "blockdev-add", "arguments": {"driver": "blkdebug", "image": "base", "node-name": "other", "take-child-perms": ["write"]}}
+{"return": {}}
+{"execute": "blockdev-backup", "arguments": {"device": "source", "sync": "full", "target": "target"}}
+{"error": {"class": "GenericError", "desc": "Cannot set permissions for backup-top filter: Conflicts with use by other as 'image', which uses 'write' on base"}}
diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
index 9d30a4b6c4..1904223020 100644
--- a/tests/qemu-iotests/group
+++ b/tests/qemu-iotests/group
@@ -289,3 +289,4 @@
279 rw backing quick
280 rw migration quick
281 rw quick
+283 auto quick
--
2.21.0
next prev parent reply other threads:[~2020-01-21 14:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-01-21 14:28 [PATCH v2 0/2] backup-top failure path fix Vladimir Sementsov-Ogievskiy
2020-01-21 14:28 ` [PATCH v2 1/2] block/backup-top: fix failure path Vladimir Sementsov-Ogievskiy
2020-01-21 14:28 ` Vladimir Sementsov-Ogievskiy [this message]
2020-01-21 16:31 ` [PATCH v2 2/2] iotests: add test for backup-top failure on permission activation Max Reitz
2020-01-21 16:32 ` [PATCH v2 0/2] backup-top failure path fix Max Reitz
2020-01-21 16:34 ` Vladimir Sementsov-Ogievskiy
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