Re: [Qemu-devel] [PATCH v5 05/11] iotests: allow resume_drive by node name

[Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>]

14.01.2019 17:46, Max Reitz wrote:
> On 29.12.18 13:20, Vladimir Sementsov-Ogievskiy wrote:
>> After node graph changes, we may not be able to resume_drive by device
>> name (backing files are not recursively searched). So, lets allow to
>> resume by node-name. Set constant name for breakpoints, to avoid
>> introducing extra parameters.
> 
> Hm, I don't quite understand this reason.  Is this so you can create
> breakpoints on one node (which falls through to the first blkdebug node)
> and then remove them from another (falling through to the same blkdebug
> node)?

add/remove breakpoint goes through ->file children, but my filter links
active disk as ->backing. So, before block-job start we can insert breakpoint
by device name. But then, when filter inserted, we can't remove breakpoint,
because my filter hides blkdebug with active disk under ->backing link.

Maybe, right solution would be support backing links in bdrv_debug_breakpoint()
and bdrv_debug_remove_breakpoint() for the case when there is no file child.

But being unsure about right behavior, I've decided to adjust the test.

What about just do both  add/remove breakpoint through blkdebug node-name, to
make it less weird?

> 
> Wouldn't it be better to let the user specify the breakpoint name?

it's not needed now. with current naming we can have one break-point in device,
so we don't need different names.

> 
> Max
> 
>> Signed-off-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
>> ---
>>   tests/qemu-iotests/iotests.py | 9 +++++----
>>   1 file changed, 5 insertions(+), 4 deletions(-)
>>
>> diff --git a/tests/qemu-iotests/iotests.py b/tests/qemu-iotests/iotests.py
>> index 76877ad584..c9779f432f 100644
>> --- a/tests/qemu-iotests/iotests.py
>> +++ b/tests/qemu-iotests/iotests.py
>> @@ -415,11 +415,11 @@ class VM(qtest.QEMUQtestMachine):
>>               self.pause_drive(drive, "write_aio")
>>               return
>>           self.qmp('human-monitor-command',
>> -                    command_line='qemu-io %s "break %s bp_%s"' % (drive, event, drive))
>> +                    command_line='qemu-io %s "break %s bp_0"' % (drive, event))
>>   
>>       def resume_drive(self, drive):
>>           self.qmp('human-monitor-command',
>> -                    command_line='qemu-io %s "remove_break bp_%s"' % (drive, drive))
>> +                    command_line='qemu-io %s "remove_break bp_0"' % (drive))
>>   
>>       def hmp_qemu_io(self, drive, cmd):
>>           '''Write to a given drive using an HMP command'''
>> @@ -543,13 +543,14 @@ class QMPTestCase(unittest.TestCase):
>>           self.assertEqual(self.vm.flatten_qmp_object(json.loads(json_filename[5:])),
>>                            self.vm.flatten_qmp_object(reference))
>>   
>> -    def cancel_and_wait(self, drive='drive0', force=False, resume=False):
>> +    def cancel_and_wait(self, drive='drive0', force=False, resume=False,
>> +                        resume_node=None):
>>           '''Cancel a block job and wait for it to finish, returning the event'''
>>           result = self.vm.qmp('block-job-cancel', device=drive, force=force)
>>           self.assert_qmp(result, 'return', {})
>>   
>>           if resume:
>> -            self.vm.resume_drive(drive)
>> +            self.vm.resume_drive(resume_node or drive)
>>   
>>           cancelled = False
>>           result = None
>>
> 
> 


-- 
Best regards,
Vladimir