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Date: Tue, 21 Sep 2010 11:43:33 +0100
Message-ID: <AANLkTinaTubQUhRWDQqQgJS+BCwzJBQ7SgikqDZSRwTf@mail.gmail.com>
Subject: Re: [Qemu-devel] Re: [PATCH] blkverify: Handle overlapping I/O vector
	buffers
From: Stefan Hajnoczi <stefanha@gmail.com>
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To: Kevin Wolf <kwolf@redhat.com>
Cc: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>, qemu-devel@nongnu.org

On Tue, Sep 21, 2010 at 11:06 AM, Kevin Wolf <kwolf@redhat.com> wrote:
> Am 20.09.2010 15:31, schrieb Stefan Hajnoczi:
>> When blkverify clones an I/O vector in order to perform mirrored reads
>> and then compare their contents, it does not take into account the
>> layout of individual buffers. =A0It turns out this is important because
>> guests may issue requests with overlapping buffers and the results
>> differ depending on how buffers are overlapped.
>>
>> This patch introduces logic to honor overlap relationships when cloning
>> I/O vectors.
>>
>> Signed-off-by: Stefan Hajnoczi <stefanha@linux.vnet.ibm.com>
>
> Took me a while to review this. These buffer calculations always look so
> harmless, but it's not trivial at all...

Thanks for the review!  I wasn't thrilled to add this logic either but
I don't see a way around it.

Will merge into blkverify so there is one unified patch including
fixes for your review comments.

Stefan