From mboxrd@z Thu Jan 1 00:00:00 1970 From: Hannes Frederic Sowa Subject: Re: [net-next PATCH 3/3] net: frag queue per hash bucket locking Date: Fri, 29 Mar 2013 01:33:08 +0100 Message-ID: <20130329003308.GD20223@order.stressinduktion.org> References: <20130327155238.15203.6688.stgit@dragon> <20130327155601.15203.25289.stgit@dragon> <1364405159.15753.26.camel@edumazet-glaptop> <20130328185721.GA20223@order.stressinduktion.org> <1364502164.15753.56.camel@edumazet-glaptop> <20130328233002.GC20223@order.stressinduktion.org> <1364513982.15753.57.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Cc: Jesper Dangaard Brouer , "David S. Miller" , netdev@vger.kernel.org, Florian Westphal , Daniel Borkmann To: Eric Dumazet Return-path: Received: from order.stressinduktion.org ([87.106.68.36]:37547 "EHLO order.stressinduktion.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753693Ab3C2AdK (ORCPT ); Thu, 28 Mar 2013 20:33:10 -0400 Content-Disposition: inline In-Reply-To: <1364513982.15753.57.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: On Thu, Mar 28, 2013 at 04:39:42PM -0700, Eric Dumazet wrote: > On Fri, 2013-03-29 at 00:30 +0100, Hannes Frederic Sowa wrote: > > On Thu, Mar 28, 2013 at 01:22:44PM -0700, Eric Dumazet wrote: > > > On Thu, 2013-03-28 at 19:57 +0100, Hannes Frederic Sowa wrote: > > > > > > > I assume that it has to do with the usage of this code in > > > > ipv6/netfilter/nf_conntrack_reasm.c, which could be invoked from process > > > > context, if I read it correctly. > > > > > > Then there would be a possible deadlock in current code. > > > > Netfilter currently does a local_bh_disable() before entering inet_fragment > > (and later enables it, again). > > > > Good, so no need for the _bh() as I suspected. Ack. I replaced the _bh spin_locks with plain spinlocks and tested the code with sending fragments and receiving fragments (netfilter and reassmbly logic) with lockdep and didn't get any splats. Looks good so far.