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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 29625C433F5 for ; Thu, 21 Oct 2021 14:08:12 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 05F9E610C8 for ; Thu, 21 Oct 2021 14:08:12 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229878AbhJUOK0 (ORCPT ); Thu, 21 Oct 2021 10:10:26 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:34398 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231425AbhJUOKX (ORCPT ); Thu, 21 Oct 2021 10:10:23 -0400 Received: from mail-oi1-x236.google.com (mail-oi1-x236.google.com [IPv6:2607:f8b0:4864:20::236]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DA9A9C061348 for ; Thu, 21 Oct 2021 07:08:07 -0700 (PDT) Received: by mail-oi1-x236.google.com with SMTP id o83so1004988oif.4 for ; Thu, 21 Oct 2021 07:08:07 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=wc/Tv1JnPe5JTHtl2WCYvQx2YZQyxySJ0ERsKW7fM8E=; b=J6bp4hyPkMyY6KBsufIevPBlG4KiyN093DyEY0n0VvFxhrgRnFeTVN4AesmKUqA36N aHrj/tEeBnYwAJwBrSyXG2FmKKHwWdq9gbotppfh7sLYfA48H39qndh4kIK+MBxHWEPo +C8NVkouyEH4ICZzrsVs6YIQT/jkNRTzTrEblcnPBHOAf3uxVW/Z/EqgFxuswe3JrYgT FP9iOVR2f+b43/WBSWhtwdQyKzFIlAq4y6hr5eRHkjZ1PxCLG6BIiVo12S3VT/B8JxPY 2Da503tahDIJDQx7W3Ig+wgew29xWFYdEKV5lUVgId6L9hVaWL7AfUp1tbpofMjHIj8a 224w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=wc/Tv1JnPe5JTHtl2WCYvQx2YZQyxySJ0ERsKW7fM8E=; b=7NI55N0OtcFo746egBpr88l8AeGUGp9rJU9XxiQOG0uA9Ttg8qpCPZ21nV9NmGvlOA SMcQcEm99GJ1N6ymmf6XQkG6a1857GvUjy7jsQ2cPJtdCxeo0ILv0Au9+yr1EaF+TICX ysZK66SiJ4ijy3RKMxKn8eZiXVF4QMUAy9tDfCYSu4CjxOZQbPQGlShNAD8Gn5uFpiFo rIf6vnAsFxD7wvMNZ73GqWEkCh7ZhK0F3bqOU+75ojGtCNzEuapC5xFklJY/yiOaxUA9 oBqImk2exAjLmswEShBxM6Dz9f8y4nRXveu+NhylpUGZ6+HZII3SuzRB44hJosa1SfYS gODw== X-Gm-Message-State: AOAM532nn71guw0d2MmqK4pGvDUJmaiIcvkIfEd/x27+H4hwGk3Q1NoR gS1WL3uMGR9N43hgJkna9Dz+6w9Kikg= X-Google-Smtp-Source: ABdhPJzyyhtJtUeJ8lejaXV4dpyY5omv3e9BaMtM5nhWJJd5QH5BEkgtItSfiC8WgMxvAaz08m+UiQ== X-Received: by 2002:a05:6808:1148:: with SMTP id u8mr4375904oiu.69.1634825287237; Thu, 21 Oct 2021 07:08:07 -0700 (PDT) Received: from [172.16.0.2] ([8.48.134.34]) by smtp.googlemail.com with ESMTPSA id h26sm944037oov.28.2021.10.21.07.08.06 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Thu, 21 Oct 2021 07:08:06 -0700 (PDT) Message-ID: <549f780b-3afb-ca30-acfe-76522bbea36a@gmail.com> Date: Thu, 21 Oct 2021 08:08:05 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.15; rv:91.0) Gecko/20100101 Thunderbird/91.2.0 Subject: Re: [PATCH v5 1/2] net: arp: introduce arp_evict_nocarrier sysctl parameter Content-Language: en-US To: James Prestwood , netdev@vger.kernel.org References: <20211021003212.878786-1-prestwoj@gmail.com> <20211021003212.878786-2-prestwoj@gmail.com> From: David Ahern In-Reply-To: <20211021003212.878786-2-prestwoj@gmail.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On 10/20/21 6:32 PM, James Prestwood wrote: > diff --git a/net/ipv4/arp.c b/net/ipv4/arp.c > index 922dd73e5740..4d3b8d1463b7 100644 > --- a/net/ipv4/arp.c > +++ b/net/ipv4/arp.c > @@ -1257,7 +1259,16 @@ static int arp_netdev_event(struct notifier_block *this, unsigned long event, > change_info = ptr; > if (change_info->flags_changed & IFF_NOARP) > neigh_changeaddr(&arp_tbl, dev); > - if (!netif_carrier_ok(dev)) > + > + rcu_read_lock(); > + in_dev = __in_dev_get_rcu(dev); > + if (!in_dev) > + evict_nocarrier = true; > + else > + evict_nocarrier = IN_DEV_ARP_EVICT_NOCARRIER(in_dev); > + rcu_read_unlock(); I believe the rtnl lock is held, so you can use __in_dev_get_rtnl and avoid the rcu_read_{,un}lock. > + > + if (evict_nocarrier && !netif_carrier_ok(dev)) > neigh_carrier_down(&arp_tbl, dev); > break; > default: