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Re: [Qemu-devel] [PATCH] quorum: don't share qiov
From: |
Wen Congyang |
Subject: |
Re: [Qemu-devel] [PATCH] quorum: don't share qiov |
Date: |
Mon, 9 Feb 2015 10:10:46 +0800 |
User-agent: |
Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 |
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
> .
>