Re: [PATCH v1 05/12] libxl: add new hotplug interface support to hotplug script callers

["Roger Pau Monné" <roger.pau@citrix.com>]

On 13/03/13 17:10, Ian Jackson wrote:
> Roger Pau Monne writes ("Re: [Xen-devel] [PATCH v1 05/12] libxl: add new hotplug interface support to hotplug script callers"):
>> On 13/03/13 15:53, Ian Jackson wrote:
>>> I think this needs a comprehensive document describing the new calling
>>> convention.  Since there isn't currently a document describing the old
>>> calling convention I think you may need to do some reverse
>>> engineering.
>>
>> Patch 11/12 adds a document describing the new calling convention.
> 
> Surely this should be in the same patch ?  In general the document for
> something should be in the same patch as the code that introduces it.
> 
> TBH I'm not sure I understand the division between the various
> patches.

I've just added it as a separate patch because I wanted to add it once
the implementation in libxl was complete, but I don't have any problem
squashing the doc into this patch.

Regarding the order of the series, I've basically added the core
functionality first in this patch, and then I went adding the missing
bits all over the other patches, trying to keep them small and concrete.

> 
>>> And then when you do that, there are things about the old calling
>>> convention which are distinctly dodgy and should perhaps be changed.
>>
>> I would prefer to avoid touching anything related to the old calling
>> convention, mainly because I would like to avoid touching the old
>> hotplug scripts in this series, and because there might be out-of-tree
>> hotplug scripts relaying on some of this obscure features.
> 
> Yes, of course.  Sorry, I was unclear.  I meant that there were
> aspects about the old calling convention which you are inheriting into
> the new one which may want to be revisited.

I'm not sure I follow you here, there's a switch in libxl__hotplug_disk
that passes completely different parameters and env vars depending on
the hotplug script version, so there's no inheritance between the old
and the new calling convention.