Date: Wed, 7 Jan 2009 20:52:18 +1100
From: Herbert Xu <herbert@gondor.apana.org.au>
To: Willy Tarreau <w@1wt.eu>
Cc: Jens Axboe <jens.axboe@oracle.com>, Evgeniy Polyakov <zbr@ioremap.net>,
       linux-kernel@vger.kernel.org, netdev@vger.kernel.org
Subject: Re: Data corruption issue with splice() on 2.6.27.10
Message-ID: <20090107095218.GA24264@gondor.apana.org.au>
References: <20081224152841.GB13113@1wt.eu> <20090106183223.GA11964@ioremap.net> <20090106183704.GC32491@kernel.dk> <20090107044232.GA22218@gondor.apana.org.au> <20090107063859.GA30749@1wt.eu>
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On Wed, Jan 07, 2009 at 07:38:59AM +0100, Willy Tarreau wrote:
>
> > Unfortunately, once the pipe is fed into sendpage we only use
> > page reference counting to pin down the memory.  So as soon as
> > sendpage returns we drop the ref count on the skb, thus freeing
> > the memory in skb->head, which is yet to be transmitted.
> 
> So this means that anything relying on sendpage() is at risk ? What

No the bug is in the splice code.  sendfile() and other sendpage
users are not affected.

Cheers,
-- 
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Email: Herbert Xu ~{PmV>HI~} <herbert@gondor.apana.org.au>
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