Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755507Ab1FFMMo (ORCPT ); Mon, 6 Jun 2011 08:12:44 -0400 Received: from mail-ww0-f44.google.com ([74.125.82.44]:51207 "EHLO mail-ww0-f44.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754302Ab1FFMMl (ORCPT ); Mon, 6 Jun 2011 08:12:41 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=subject:from:to:cc:in-reply-to:references:content-type:date :message-id:mime-version:x-mailer:content-transfer-encoding; b=doLd+E0Jc3V8QPyd74kbEb97li5ymLmB9SlcDhdnVny+s5JV0d4i1BTu8w4dqeo3/3 tSu8zv69BpOCFnJx3Jz+YrJJUjQ2lkocpj9jvbyyDFfCNL62q3QsfGkuDgNLdLq8vcX+ +SjKDc4iyazvEaVaQRH5vZQbdqNo6eW5M1sAE= Subject: Re: bridge/netfilter: regression in 2.6.39.1 From: Eric Dumazet To: Alexander Holler Cc: Neil Horman , linux-kernel@vger.kernel.org, David Miller , Herbert Xu , netdev@vger.kernel.org In-Reply-To: <4DECBEA3.6070408@ahsoftware.de> References: <4DE93422.3070000@ahsoftware.de> <20110606111507.GA1000@hmsreliant.think-freely.org> <4DECBEA3.6070408@ahsoftware.de> Content-Type: text/plain; charset="UTF-8" Date: Mon, 06 Jun 2011 14:12:37 +0200 Message-ID: <1307362358.3098.6.camel@edumazet-laptop> Mime-Version: 1.0 X-Mailer: Evolution 2.32.2 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1934 Lines: 58 Le lundi 06 juin 2011 à 13:48 +0200, Alexander Holler a écrit : > Am 06.06.2011 13:15, schrieb Neil Horman: > > On Fri, Jun 03, 2011 at 09:21:06PM +0200, Alexander Holler wrote: > >> Hello, > >> > >> I'm getting a oops in the bridge code in br_change_mtu() with > >> 2.6.39.1. The patch below seems to fix that. > >> > >> I'm not sure about the usage of dst_cow_metrics_generic() in > >> fake_dst_ops, but after having a quick look at it seems to be ok to > >> use that here. > >> > >> Regards, > >> > >> Alexander > >> > > How did the flags of the dst entry on which we're callnig dst_entry_write_ptr > > wind up getting the READ_ONLY flag set on it? I don't see how we'er falling > > into that clause in which we call cow_metrics when we call dst_metric_set. It > > seems like that flag is set erroneously. perhaps we should just update > > fake_rtable.dst to have the correct flags? > > Neil > > It is set by that change: > > -------- > @@ -124,7 +128,7 @@ void br_netfilter_rtable_init(struct net_bridge *br) > atomic_set(&rt->dst.__refcnt, 1); > rt->dst.dev = br->dev; > rt->dst.path = &rt->dst; > - dst_metric_set(&rt->dst, RTAX_MTU, 1500); > + dst_init_metrics(&rt->dst, br_dst_default_metrics, true); > rt->dst.flags = DST_NOXFRM; > rt->dst.ops = &fake_dst_ops; > } > -------- > > The true in dst_init_metrics() is responsible for that flag. > You are aware this change fixed an oops ? read_only in this context means : In case this must be written, we make a COW first (allocate a piece of memory, copy the source in it before applying any change) It would be nice you send us the stack trace, so that we can have a clue of whats going on. Thanks -- 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/