Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754135AbZAGMZK (ORCPT ); Wed, 7 Jan 2009 07:25:10 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751524AbZAGMYy (ORCPT ); Wed, 7 Jan 2009 07:24:54 -0500 Received: from rhun.apana.org.au ([64.62.148.172]:38679 "EHLO arnor.apana.org.au" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751481AbZAGMYx (ORCPT ); Wed, 7 Jan 2009 07:24:53 -0500 Date: Wed, 7 Jan 2009 23:24:07 +1100 From: Herbert Xu To: Willy Tarreau Cc: Jarek Poplawski , Jens Axboe , Changli Gao , Evgeniy Polyakov , linux-kernel@vger.kernel.org, netdev@vger.kernel.org Subject: Re: Data corruption issue with splice() on 2.6.27.10 Message-ID: <20090107122407.GC25673@gondor.apana.org.au> References: <20081224152841.GB13113@1wt.eu> <20090106085442.GA9513@ff.dom.local> <20090106094138.GE25644@1wt.eu> <20090106100112.GB9513@ff.dom.local> <20090106155715.GA28783@1wt.eu> <20090107093915.GA6899@ff.dom.local> <20090107122205.GA6051@1wt.eu> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20090107122205.GA6051@1wt.eu> User-Agent: Mutt/1.5.18 (2008-05-17) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1444 Lines: 41 On Wed, Jan 07, 2009 at 01:22:05PM +0100, Willy Tarreau wrote: > > > diff --git a/net/core/skbuff.c b/net/core/skbuff.c > > index 5110b35..4c080cd 100644 > > --- a/net/core/skbuff.c > > +++ b/net/core/skbuff.c > > @@ -73,17 +73,13 @@ static struct kmem_cache *skbuff_fclone_cache __read_mostly; > > static void sock_pipe_buf_release(struct pipe_inode_info *pipe, > > struct pipe_buffer *buf) > > { > > - struct sk_buff *skb = (struct sk_buff *) buf->private; > > - > > - kfree_skb(skb); > > + put_page(buf->page); > > } > > > > static void sock_pipe_buf_get(struct pipe_inode_info *pipe, > > struct pipe_buffer *buf) > > { > > - struct sk_buff *skb = (struct sk_buff *) buf->private; > > - > > - skb_get(skb); > > + get_page(buf->page); > > } Well this patch can only make it worse because not only are you still ref counting skb->head with get_page, but you've also completely removed the skb ref count which means that the corruption can only occur sooner. Cheers, -- Visit Openswan at http://www.openswan.org/ Email: Herbert Xu ~{PmV>HI~} Home Page: http://gondor.apana.org.au/~herbert/ PGP Key: http://gondor.apana.org.au/~herbert/pubkey.txt -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/