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Date: Tue, 26 Jul 2011 16:54:10 +0200
From: Kevin Wolf <kwolf@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v3] Add support for fd: protocol
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To: Corey Bryant <bryntcor@us.ibm.com>
Cc: aliguori@us.ibm.com, libvir-list@redhat.com, Corey Bryant <coreyb@linux.vnet.ibm.com>, qemu-devel@nongnu.org, tchicks@us.ibm.com, Christoph Hellwig <hch@lst.de>

Am 26.07.2011 16:46, schrieb Corey Bryant:
> 
> On 07/26/2011 10:05 AM, Kevin Wolf wrote:
>> Am 26.07.2011 15:02, schrieb Christoph Hellwig:
>>>>  I have to say I really hate it.  We've been working hard on getting rid
>>>>  of special cases in the qemu block layer, and this sprinkles them all
>>>>  over.  I'd recommend to fix your security model instead.
>> I think the problem here is more with the implementation that with the
>> intention.
>>
>> I agree that you just can't do this. A patch adding support for a fd:
>> protocol should touch block/fd.c and nothing else. You can add some
>> supporting patches that extend the generic block layer to support e.g.
>> formats that can't reopen. However, if you touch the code of other block
>> drivers, you're doing it wrong.
> 
> I'll look into this approach, but on the surface it seems like this 
> could prevent a lot of code reuse in block/raw-posix.c.

What I meant here is more about modifying qcow2, VMDK etc. I still need
to look into the details of what you share with raw-posix.c.

Kevin