Re: [Qemu-devel] [PATCH v4 10/10] iotests: test nbd reconnect

[Vladimir Sementsov-Ogievskiy]

16.01.2019 20:11, Eric Blake wrote:
> On 7/31/18 12:30 PM, Vladimir Sementsov-Ogievskiy wrote:
>> Add test, which starts backup to nbd target and restarts nbd server
>> during backup.
>>
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <address@hidden>
>> ---
>>   tests/qemu-iotests/220        | 67 
>> +++++++++++++++++++++++++++++++++++++++++++
>>   tests/qemu-iotests/220.out    |  7 +++++
>>   tests/qemu-iotests/group      |  1 +
>>   tests/qemu-iotests/iotests.py |  4 +++
>>   4 files changed, 79 insertions(+)
>>   create mode 100755 tests/qemu-iotests/220
>>   create mode 100644 tests/qemu-iotests/220.out
>>
> 
> Test 220 has been created in the meantime; the obvious resolution is to
> pick a new test number.
> 
>> diff --git a/tests/qemu-iotests/220 b/tests/qemu-iotests/220
>> new file mode 100755
>> index 0000000000..c9702a7dad
>> --- /dev/null
>> +++ b/tests/qemu-iotests/220
>> @@ -0,0 +1,67 @@
>> +#!/usr/bin/env python
> 
>> +
>> +import iotests
>> +from iotests import qemu_img_create, file_path, qemu_nbd_popen
>> +
>> +disk_a, disk_b, nbd_sock = file_path('disk_a', 'disk_b', 'nbd-sock')
>> +nbd_uri = 'nbd+unix:///exp?socket=' + nbd_sock
>> +
>> +qemu_img_create('-f', iotests.imgfmt, disk_a, '5M')
>> +qemu_img_create('-f', iotests.imgfmt, disk_b, '5M')
>> +srv = qemu_nbd_popen('-k', nbd_sock, '-x', 'exp', '-f', iotests.imgfmt, 
>> disk_b)
>> +time.sleep(1)
>> +
>> +vm = iotests.VM().add_drive(disk_a)
>> +vm.launch()
>> +vm.hmp_qemu_io('drive0', 'write 0 5M')
>> +
>> +print 'blockdev-add:', vm.qmp('blockdev-add', node_name='backup0', 
>> driver='raw',
>> +                              file={'driver':'nbd',
>> +                                    'export': 'exp',
>> +                                    'server': {'type': 'unix',
>> +                                               'path': nbd_sock}})
>> +print 'blockdev-backup:', vm.qmp('blockdev-backup', device='drive0',
>> +                                 sync='full', target='backup0')
>> +
>> +time.sleep(1)
>> +print 'Kill NBD server'
>> +srv.kill()
>> +
>> +jobs = vm.qmp('query-block-jobs')['return']
>> +if jobs and jobs[0]['offset'] < jobs[0]['len']:
>> +    print 'Backup job is still in progress'
>> +
>> +time.sleep(1)
> 
> That's a lot of sleep()s for a test marked quick. Are we sure it won't
> fail under heavy load? Can you make the test more reliable by looking
> for specific events rather than just a fixed-length sleep?

Hmm.. 3 seconds is still quick I think.

Firstly I want nbd server to be actually started, but it has no events. Then I 
want
backup to do some progress, again, no event for progress. And the last one 
actual server
unavailable time.. So, I don't have better idea.

> 
>> +
>> +print 'Start NBD server'
>> +srv = qemu_nbd_popen('-k', nbd_sock, '-x', 'exp', '-f', iotests.imgfmt, 
>> disk_b)
>> +
>> +try:
>> +    e = vm.event_wait('BLOCK_JOB_COMPLETED')
>> +    print e['event'], ':', e['data']
>> +except:
>> +    pass
>> +
>> +print 'blockdev-del:', vm.qmp('blockdev-del', node_name='backup0')
>> +srv.kill()
>> +vm.shutdown()
>> diff --git a/tests/qemu-iotests/220.out b/tests/qemu-iotests/220.out
>> new file mode 100644
>> index 0000000000..dae1a49d9f
>> --- /dev/null
>> +++ b/tests/qemu-iotests/220.out
>> @@ -0,0 +1,7 @@
>> +blockdev-add: {u'return': {}}
>> +blockdev-backup: {u'return': {}}
>> +Kill NBD server
>> +Backup job is still in progress
>> +Start NBD server
>> +BLOCK_JOB_COMPLETED : {u'device': u'drive0', u'type': u'backup', u'speed': 
>> 0, u'len': 5242880, u'offset': 5242880}
>> +blockdev-del: {u'return': {}}
>> diff --git a/tests/qemu-iotests/group b/tests/qemu-iotests/group
>> index b973dc842d..ee2473c6a3 100644
>> --- a/tests/qemu-iotests/group
>> +++ b/tests/qemu-iotests/group
>> @@ -219,6 +219,7 @@
>>   217 rw auto quick
>>   218 rw auto quick
>>   219 rw auto
>> +220 rw auto quick
>>   221 rw auto quick
>>   222 rw auto quick
>>   223 rw auto quick
>> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
>> index 4e67fbbe96..17bc8c8e32 100644
>> --- a/tests/qemu-iotests/iotests.py
>> +++ b/tests/qemu-iotests/iotests.py
>> @@ -185,6 +185,10 @@ def qemu_nbd(*args):
>>       '''Run qemu-nbd in daemon mode and return the parent's exit code'''
>>       return subprocess.call(qemu_nbd_args + ['--fork'] + list(args))
>>   
>> +def qemu_nbd_popen(*args):
>> +    '''Run qemu-nbd in daemon mode and return the parent's exit code'''
>> +    return subprocess.Popen(qemu_nbd_args + ['--persistent'] + list(args))
>> +
>>   def compare_images(img1, img2, fmt1=imgfmt, fmt2=imgfmt):
>>       '''Return True if two image files are identical'''
>>       return qemu_img('compare', '-f', fmt1,
>>
> 


-- 
Best regards,
Vladimir