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Message-ID: <54D81726.9060000@cn.fujitsu.com>
Date: Mon, 9 Feb 2015 10:10:46 +0800
From: Wen Congyang <wency@cn.fujitsu.com>
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Subject: Re: [Qemu-devel] [PATCH] quorum: don't share qiov
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To: Kevin Wolf <kwolf@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, qemu-devl <qemu-devel@nongnu.org>, Stefan Hajnoczi <stefanha@redhat.com>

On 02/03/2015 07:01 PM, Paolo Bonzini wrote:
> 
> 
> On 03/02/2015 10:22, Kevin Wolf wrote:
>> Paolo, I think it's rather surprising that iov_send_recv() modifies its
>> iov. The modification is undone at the end, so you seem to have
>> considered that a caller might be reusing it after and you can't "use it
>> up", but we still get problems with concurrent accesses.
> 
> Yes, I wasn't thinking of concurrent accesses indeed.  But I wasn't the
> author of iov_send_recv(), I just took it from sheepdog. :)
> 
>> Was it an intentional design decision that iov_send_recv() is the sole
>> owner of the iov and the caller must duplicate it if it's used elsewhere
>> concurrently?
>>
>> Otherwise I would suggest to fix iov_send_recv(), and possibly try and
>> make all the qiov/iov arguments in the block layer const.
> 
> I agree.  However, it's not a small change.  I think Wen's patch is okay
> with a FIXME comment added.

Hi, kevin

What should I do next? Add a comment and resend it?

Thanks
Wen Congyang

> 
> Paolo
> .
>