Re: [Qemu-devel] [PATCH] Add tar container format

[Anthony Liguori <anthony@codemonkey.ws>]

Alexander Graf wrote:
>
>> I'd almost rather see something like gio integration so that this 
>> sort of generic filesystem stuff could live somewhere else.  I'm 
>> curious what others think though.  Does it seem reasonable to include 
>> this type of functionality?
>
>
> A plugin infrastructure sounds nice at first, but doesn't do all the 
> fedoras and ubuntus out there too much good ;-).

If we did plugins, it would not be a GPL-safe boundary so all plugins 
would be forced to be GPL.

What's attractive about doing plugins for the block layer is that we 
have a relatively stable interface for block drivers.  The current AIO 
ops should be good for a very long time so API churn shouldn't be a 
major issue.  The code is all pretty well isolated today.

As part of the longer term refactoring, I think it also makes sense to 
split the block layer into a library that can be consumed independent of 
QEMU.  Obviously, folks want to make use of our block code who don't 
care at all about QEMU.  A lot of people use qemu-img for vmdk 
manipulation, for instance.  It also makes tools like qemu-iotest able 
to consume the block layer in a saner way.

If others agree, I think we should start going down this road.  
block-tar/block-dictzip seem like obvious candidates for plugins.

Regards,

Anthony Liguori

> Alex