From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id C681DC54E8E for ; Sun, 10 May 2020 22:14:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B243C20708 for ; Sun, 10 May 2020 22:14:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729410AbgEJWOj (ORCPT ); Sun, 10 May 2020 18:14:39 -0400 Received: from correo.us.es ([193.147.175.20]:38840 "EHLO mail.us.es" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728763AbgEJWOj (ORCPT ); Sun, 10 May 2020 18:14:39 -0400 Received: from antivirus1-rhel7.int (unknown [192.168.2.11]) by mail.us.es (Postfix) with ESMTP id 6563F117724 for ; Mon, 11 May 2020 00:14:37 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 551F811540C for ; Mon, 11 May 2020 00:14:37 +0200 (CEST) Received: by antivirus1-rhel7.int (Postfix, from userid 99) id 4A1C6DA736; Mon, 11 May 2020 00:14:37 +0200 (CEST) Received: from antivirus1-rhel7.int (localhost [127.0.0.1]) by antivirus1-rhel7.int (Postfix) with ESMTP id 5A4E3A6A0; Mon, 11 May 2020 00:14:35 +0200 (CEST) Received: from 192.168.1.97 (192.168.1.97) by antivirus1-rhel7.int (F-Secure/fsigk_smtp/550/antivirus1-rhel7.int); Mon, 11 May 2020 00:14:35 +0200 (CEST) X-Virus-Status: clean(F-Secure/fsigk_smtp/550/antivirus1-rhel7.int) Received: from us.es (unknown [90.77.255.23]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) (Authenticated sender: 1984lsi) by entrada.int (Postfix) with ESMTPSA id 3DA0842EF4E0; Mon, 11 May 2020 00:14:35 +0200 (CEST) Date: Mon, 11 May 2020 00:14:34 +0200 X-SMTPAUTHUS: auth mail.us.es From: Pablo Neira Ayuso To: Paul Blakey Cc: Oz Shlomo , Roi Dayan , netdev@vger.kernel.org, Saeed Mahameed , netfilter-devel@vger.kernel.org Subject: Re: [PATCH net] netfilter: flowtable: Add pending bit for offload work Message-ID: <20200510221434.GA11226@salvia> References: <1588764279-12166-1-git-send-email-paulb@mellanox.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1588764279-12166-1-git-send-email-paulb@mellanox.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-Virus-Scanned: ClamAV using ClamSMTP Sender: netfilter-devel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netfilter-devel@vger.kernel.org Hi, On Wed, May 06, 2020 at 02:24:39PM +0300, Paul Blakey wrote: > Gc step can queue offloaded flow del work or stats work. > Those work items can race each other and a flow could be freed > before the stats work is executed and querying it. > To avoid that, add a pending bit that if a work exists for a flow > don't queue another work for it. > This will also avoid adding multiple stats works in case stats work > didn't complete but gc step started again. This is happening since the mutex has been removed, right? Another question below. > Signed-off-by: Paul Blakey > Reviewed-by: Roi Dayan > --- > include/net/netfilter/nf_flow_table.h | 1 + > net/netfilter/nf_flow_table_offload.c | 8 +++++++- > 2 files changed, 8 insertions(+), 1 deletion(-) > > diff --git a/include/net/netfilter/nf_flow_table.h b/include/net/netfilter/nf_flow_table.h > index 6bf6965..c54a7f7 100644 > --- a/include/net/netfilter/nf_flow_table.h > +++ b/include/net/netfilter/nf_flow_table.h > @@ -127,6 +127,7 @@ enum nf_flow_flags { > NF_FLOW_HW_DYING, > NF_FLOW_HW_DEAD, > NF_FLOW_HW_REFRESH, > + NF_FLOW_HW_PENDING, > }; > > enum flow_offload_type { > diff --git a/net/netfilter/nf_flow_table_offload.c b/net/netfilter/nf_flow_table_offload.c > index b9d5ecc..731d738 100644 > --- a/net/netfilter/nf_flow_table_offload.c > +++ b/net/netfilter/nf_flow_table_offload.c > @@ -817,6 +817,7 @@ static void flow_offload_work_handler(struct work_struct *work) > WARN_ON_ONCE(1); > } > > + clear_bit(NF_FLOW_HW_PENDING, &offload->flow->flags); > kfree(offload); > } > > @@ -831,9 +832,14 @@ static void flow_offload_queue_work(struct flow_offload_work *offload) > { > struct flow_offload_work *offload; > > + if (test_and_set_bit(NF_FLOW_HW_PENDING, &flow->flags)) > + return NULL; In case of stats, it's fine to lose work. But how does this work for the deletion case? Does this falls back to the timeout deletion? Thanks.