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

[Vladimir Sementsov-Ogievskiy]

23.01.2019 16:22, Vladimir Sementsov-Ogievskiy wrote:
> 16.01.2019 16:11, Max Reitz wrote:
>> On 14.01.19 17:06, Vladimir Sementsov-Ogievskiy wrote:
>>> 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?
>>
>> Yes, I was mostly wondering about the "set constant name for
>> breakpoints".  It doesn't seem necessary to me;
> 
> It's just to not create extra parameters or something. Current code don't 
> allow
> to create several breakpoints in one blkdebug anyway (as @drive is used as
> breakpoint name), so there is no reason for different names at all.
> 
> I'll improve commit message to make it clean.
> 

Hmmm.

Or, finally, may be better to teach bdrv_debug_breakpoint() and
bdrv_debug_remove_breakpoint() to skip filters with backing child?


-- 
Best regards,
Vladimir