Re: [Qemu-devel] [PATCH 1/3] iotests: add test 255 to check bitmap life after snapshot + commit

[John Snow <jsnow@redhat.com>]

On 5/23/19 11:47 AM, Vladimir Sementsov-Ogievskiy wrote:
> Two testcases with persistent bitmaps are not added here, as there are
> bugs to be fixed soon.
> 
> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
> ---
>  python/qemu/__init__.py    |  4 +-
>  tests/qemu-iotests/255     | 81 ++++++++++++++++++++++++++++++++++++++
>  tests/qemu-iotests/255.out | 17 ++++++++
>  tests/qemu-iotests/group   |  1 +
>  4 files changed, 102 insertions(+), 1 deletion(-)
>  create mode 100755 tests/qemu-iotests/255
>  create mode 100644 tests/qemu-iotests/255.out
> 
> diff --git a/python/qemu/__init__.py b/python/qemu/__init__.py
> index 81d9657ec0..4c4317a55e 100644
> --- a/python/qemu/__init__.py
> +++ b/python/qemu/__init__.py
> @@ -402,7 +402,7 @@ class QEMUMachine(object):
>          self._qmp.clear_events()
>          return events
>  
> -    def event_wait(self, name, timeout=60.0, match=None):
> +    def event_wait(self, name, timeout=60.0, match=None, fail_on=None):
>          """
>          Wait for specified timeout on named event in QMP; optionally filter
>          results by match.
> @@ -430,6 +430,7 @@ class QEMUMachine(object):
>  
>          # Search cached events
>          for event in self._events:
> +            assert event['event'] != fail_on
>              if (event['event'] == name) and event_match(event, match):
>                  self._events.remove(event)
>                  return event
> @@ -437,6 +438,7 @@ class QEMUMachine(object):
>          # Poll for new events
>          while True:
>              event = self._qmp.pull_event(wait=timeout)
> +            assert event['event'] != fail_on
>              if (event['event'] == name) and event_match(event, match):
>                  return event
>              self._events.append(event)

I'd rather not put assertions directly in the QEMUMachine code, unless
it's actually an assertion and not a test failure, because this code is
not necessarily meant to be used exclusively for tests.

> diff --git a/tests/qemu-iotests/255 b/tests/qemu-iotests/255
> new file mode 100755
> index 0000000000..36712689d3
> --- /dev/null
> +++ b/tests/qemu-iotests/255
> @@ -0,0 +1,81 @@
> +#!/usr/bin/env python
> +#
> +# Tests for temporary external snapshot when we have bitmaps.
> +#
> +# Copyright (c) 2019 Virtuozzo International GmbH. All rights reserved.
> +#
> +# 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
> +from iotests import qemu_img_create, file_path, log
> +
> +iotests.verify_image_format(supported_fmts=['qcow2'])
> +
> +base, top = file_path('base', 'top')
> +size = 64 * 1024 * 3
> +
> +
> +def print_bitmap(msg, vm):
> +    result = vm.qmp('query-block')['return'][0]
> +    if 'dirty-bitmaps' in result:
> +        bitmap = result['dirty-bitmaps'][0]
> +        log('{}: name={} dirty-clusters={}'.format(msg, bitmap['name'],
> +            bitmap['count'] // 64 // 1024))
> +    else:
> +        log(msg + ': not found')
> +
> +
> +def test(persistent, restart):
> +    assert persistent or not restart
> +    log("\nTestcase {}persistent {} restart\n".format(
> +            '' if persistent else 'non-', 'with' if restart else 'without'))
> +
> +    qemu_img_create('-f', iotests.imgfmt, base, str(size))
> +
> +    vm = iotests.VM().add_drive(base)
> +    vm.launch()
> +
> +    vm.qmp_log('block-dirty-bitmap-add', node='drive0', name='bitmap0',
> +               persistent=persistent)
> +    vm.hmp_qemu_io('drive0', 'write 0 64K')
> +    print_bitmap('initial bitmap', vm)
> +
> +    vm.qmp_log('blockdev-snapshot-sync', device='drive0', snapshot_file=top,
> +               format=iotests.imgfmt, filters=[iotests.filter_qmp_testfiles])
> +    vm.hmp_qemu_io('drive0', 'write 64K 512')
> +    print_bitmap('check, that no bitmaps in snapshot', vm)

'check that no bitmaps are in snapshot', probably.

> +
> +    if restart:
> +        log("... Restart ...")
> +        vm.shutdown()
> +        vm = iotests.VM().add_drive(top)
> +        vm.launch()
> +
> +    vm.qmp_log('block-commit', device='drive0', top=top,
> +               filters=[iotests.filter_qmp_testfiles])
> +    log(vm.event_wait('BLOCK_JOB_READY', fail_on='BLOCK_JOB_COMPLETED'),
> +        filters=[iotests.filter_qmp_event])

Looks like you probably saw some interesting things during development.
You shouldn't see COMPLETED before READY, should you? Is this necessary?

> +    vm.qmp_log('block-job-complete', device='drive0')
> +    log(vm.event_wait('BLOCK_JOB_COMPLETED'),
> +        filters=[iotests.filter_qmp_event])

(Just musing: we probably want a filtered version of event_wait for
iotests.py so we don't have to type this so much.)

> +    print_bitmap('check merged bitmap', vm)
> +

Merged? We don't /merge/ the bitmaps, do we? I guess you mean to say
something like: "Check bitmaps on merged/converged node", right?

> +    vm.hmp_qemu_io('drive0', 'write 128K 64K')
> +    print_bitmap('check updated bitmap', vm)
> +
> +    vm.shutdown()
> +
> +
> +test(persistent=False, restart=False)
> diff --git a/tests/qemu-iotests/255.out b/tests/qemu-iotests/255.out
> new file mode 100644
> index 0000000000..2bffb486d2
> --- /dev/null
> +++ b/tests/qemu-iotests/255.out
> @@ -0,0 +1,17 @@
> +
> +Testcase non-persistent without restart
> +
> +{"execute": "block-dirty-bitmap-add", "arguments": {"name": "bitmap0", "node": "drive0", "persistent": false}}
> +{"return": {}}
> +initial bitmap: name=bitmap0 dirty-clusters=1
> +{"execute": "blockdev-snapshot-sync", "arguments": {"device": "drive0", "format": "qcow2", "snapshot-file": "TEST_DIR/PID-top"}}
> +{"return": {}}
> +check, that no bitmaps in snapshot: not found
> +{"execute": "block-commit", "arguments": {"device": "drive0", "top": "TEST_DIR/PID-top"}}
> +{"return": {}}
> +{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_READY", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
> +{"execute": "block-job-complete", "arguments": {"device": "drive0"}}
> +{"return": {}}
> +{"data": {"device": "drive0", "len": 65536, "offset": 65536, "speed": 0, "type": "commit"}, "event": "BLOCK_JOB_COMPLETED", "timestamp": {"microseconds": "USECS", "seconds": "SECS"}}
> +check merged bitmap: name=bitmap0 dirty-clusters=2
> +check updated bitmap: name=bitmap0 dirty-clusters=3
> diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
> index 52b7c16e15..2758f48143 100644
> --- a/tests/qemu-iotests/group
> +++ b/tests/qemu-iotests/group
> @@ -251,3 +251,4 @@
>  249 rw auto quick
>  252 rw auto backing quick
>  253 rw auto quick
> +255 rw auto quick
> 

Good test, I just have to dig through patch 3.