From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756911AbaIWVjZ (ORCPT ); Tue, 23 Sep 2014 17:39:25 -0400 Received: from mail.us.es ([193.147.175.20]:44162 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756823AbaIWVjX (ORCPT ); Tue, 23 Sep 2014 17:39:23 -0400 X-Qmail-Scanner-Diagnostics: from 127.0.0.1 by antivirus2 (envelope-from , uid 501) with qmail-scanner-2.10 (clamdscan: 0.98.4/19423. spamassassin: 3.3.2. Clear:RC:1(127.0.0.1):SA:0(-103.2/7.5):. Processed in 2.040677 secs); 23 Sep 2014 21:39:20 -0000 X-Spam-ASN: AS12715 87.216.0.0/16 X-Envelope-From: pneira@us.es Date: Tue, 23 Sep 2014 23:40:21 +0200 From: Pablo Neira Ayuso To: Ben Hutchings Cc: Rob Jones , davem@davemloft.net, coreteam@netfilter.org, netdev@vger.kernel.org, linux-kernel@codethink.co.uk, linux-kernel@vger.kernel.org, netfilter@vger.kernel.org, netfilter-devel@vger.kernel.org Subject: Re: [Linux-kernel] [PATCH v2] net/netfilter/x_tables.c: use __seq_open_private() Message-ID: <20140923214021.GA4206@salvia> References: <1411491955-9131-1-git-send-email-rob.jones@codethink.co.uk> <1411494387.32579.138.camel@xylophone> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1411494387.32579.138.camel@xylophone> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Sep 23, 2014 at 06:46:27PM +0100, Ben Hutchings wrote: > On Tue, 2014-09-23 at 18:05 +0100, Rob Jones wrote: > > Reduce boilerplate code by using __seq_open_private() instead of seq_open() > > in xt_match_open() and xt_target_open(). > > > > Signed-off-by: Rob Jones > > --- > > > > This patch uses an existing variant of seq_open() to reduce the kernel code > > size. > > > > The only significant variation from the pre-existing code is the fact that > > __seq_open_private() calls kzalloc() rather than kmalloc(), which could > > conceivably have an impact on timing. > > > > This version 2 incorporates a minor initialisation simplification (resulting > > from kzalloc() being used) requested by netfilter-devel@vger.kernel.org > [...] > > --- a/net/netfilter/x_tables.c > > +++ b/net/netfilter/x_tables.c > > @@ -1080,7 +1080,6 @@ static void *xt_mttg_seq_start(struct seq_file *seq, loff_t *pos, > > struct nf_mttg_trav *trav = seq->private; > > unsigned int j; > > > > - trav->class = MTTG_TRAV_INIT; > > for (j = 0; j < *pos; ++j) > > if (xt_mttg_seq_next(seq, NULL, NULL, is_target) == NULL) > > return NULL; > [...] > > I'm fairly sure this simplification is wrong, as xt_mttg_seq_start() is > potentially called multiple times on the same file handle. Right. I'm going to take v1 of this patch instead, sorry for the inconvenience Rob.