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=-9.3 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A, 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 CC985C433E0 for ; Mon, 29 Mar 2021 19:57:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 8DF1A601FC for ; Mon, 29 Mar 2021 19:57:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231709AbhC2T4z (ORCPT ); Mon, 29 Mar 2021 15:56:55 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:59786 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231512AbhC2T4h (ORCPT ); Mon, 29 Mar 2021 15:56:37 -0400 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id B6E73C061574; Mon, 29 Mar 2021 12:56:36 -0700 (PDT) Received: by mail-wm1-x32b.google.com with SMTP id m20-20020a7bcb940000b029010cab7e5a9fso9096670wmi.3; Mon, 29 Mar 2021 12:56:36 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=MQBrb4YVkXVVUdNQVIYjRBD1ELh8gLe+l+iTh/6ZeHE=; b=apoBR01O0o2kiwhvAkciBfD7GZFv1B/yax9UQcmq8NLg7THJXp9CqywQmRY0GATMB8 2pN66eybFsOGXRE5+Au+grXwApxl8fjIJSMtONFCmGjAf1Nv2+ki6LLABqPWZzgiSET6 bTllyR8Zc81quWkKoo2E4zphFgY1NWZfD/IERlV6jNEbWU7yKf6LLxkzYYRKWM+oRmGw vaalZARYxt85174gBzFKUBe0gvnQcoN+roAFMsPVbON0q6eoAie9Q//Zgr+xjLXNHadu DVH7vezu4UgnyXOUQhwaJQ3r6M5xMFPrvkzIc7WTnSdpx6IshSgwMZBTmfzg24F2pwot Zk9Q== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:message-id:date :user-agent:mime-version:in-reply-to:content-language :content-transfer-encoding; bh=MQBrb4YVkXVVUdNQVIYjRBD1ELh8gLe+l+iTh/6ZeHE=; b=qOSlKQMvfiMbv5mOvc9N+W0r+mSMdqYzXAQy+mTJ6c+kSUl8HVn3zN1j1dDUAunGnN PHNSUp12/W60O7vhW9g1d7Q/VyJqvkg7RQZVhcrkqnploycmj9oA5qD1Nkgv/KEYQhRf NU4pICGUHXLBV9HJP/Q4TdgWao2y4Id4wDx6cPOswcBM0LPDYW7CTR8IKniW2QqhpZWB ZkTKzSk36FNBE0UwVw5jUDDUMfQQF2URi1cLc5PSnqc2hNzr7Iq5aGYc/0hcBv3VMuIP tSiFXfxLbJ8iYPZEsxcOQzCws5zGLbBXj31oXghRunJbUYPYUKOq0s9IbGsJjj5Xa4/j 8bDg== X-Gm-Message-State: AOAM533Utk9u/8EQpYjoUPR8KFGlOTgpG+M0oMg1lls1MStT9Rcked2s sDaiHVZOYw7VY2WwAOe/9Xw= X-Google-Smtp-Source: ABdhPJzaPyymGOXg3cichgFoBPMx6tnYRHhCJYXcLD4ZgPv84qLD+ONtlhrSVvSSIa0vQXYxzmbxjw== X-Received: by 2002:a1c:3d8a:: with SMTP id k132mr590836wma.71.1617047795554; Mon, 29 Mar 2021 12:56:35 -0700 (PDT) Received: from [192.168.1.101] ([37.173.175.207]) by smtp.gmail.com with ESMTPSA id f2sm457550wmp.20.2021.03.29.12.56.32 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 29 Mar 2021 12:56:35 -0700 (PDT) Subject: Re: [PATCH net-next v3 5/7] mld: convert ifmcaddr6 to RCU To: Taehee Yoo , netdev@vger.kernel.org, davem@davemloft.net, kuba@kernel.org Cc: jwi@linux.ibm.com, kgraul@linux.ibm.com, hca@linux.ibm.com, gor@linux.ibm.com, borntraeger@de.ibm.com, mareklindner@neomailbox.ch, sw@simonwunderlich.de, a@unstable.cc, sven@narfation.org, yoshfuji@linux-ipv6.org, dsahern@kernel.org, linux-s390@vger.kernel.org, b.a.t.m.a.n@lists.open-mesh.org References: <20210325161657.10517-1-ap420073@gmail.com> <20210325161657.10517-6-ap420073@gmail.com> From: Eric Dumazet Message-ID: <6262890a-7789-e3dd-aa04-58e5e06499dc@gmail.com> Date: Mon, 29 Mar 2021 21:56:32 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.8.0 MIME-Version: 1.0 In-Reply-To: <20210325161657.10517-6-ap420073@gmail.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-s390@vger.kernel.org On 3/25/21 5:16 PM, Taehee Yoo wrote: > The ifmcaddr6 has been protected by inet6_dev->lock(rwlock) so that > the critical section is atomic context. In order to switch this context, > changing locking is needed. The ifmcaddr6 actually already protected by > RTNL So if it's converted to use RCU, its control path context can be > switched to sleepable. > I do not really understand the changelog. You wanted to convert from RCU to RTNL, right ? Also : > @@ -571,13 +573,9 @@ int ip6_mc_msfget(struct sock *sk, struct group_filter *gsf, > if (!ipv6_addr_is_multicast(group)) > return -EINVAL; > > - rcu_read_lock(); > - idev = ip6_mc_find_dev_rcu(net, group, gsf->gf_interface); > - > - if (!idev) { > - rcu_read_unlock(); > + idev = ip6_mc_find_dev_rtnl(net, group, gsf->gf_interface); > + if (!idev) > return -ENODEV; > - } > I do not see RTNL being acquired before entering ip6_mc_msfget()