From patchwork Thu Sep 3 08:54:52 2020 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Tom Parkin X-Patchwork-Id: 261588 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=-13.1 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH, MAILING_LIST_MULTI, SIGNED_OFF_BY, SPF_HELO_NONE, SPF_PASS, URIBL_BLOCKED, USER_AGENT_GIT 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 3749BC433E7 for ; Thu, 3 Sep 2020 08:55:19 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F23CC2065F for ; Thu, 3 Sep 2020 08:55:18 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=katalix.com header.i=@katalix.com header.b="ORVNv6uQ" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728308AbgICIzS (ORCPT ); Thu, 3 Sep 2020 04:55:18 -0400 Received: from mail.katalix.com ([3.9.82.81]:42260 "EHLO mail.katalix.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726567AbgICIzJ (ORCPT ); Thu, 3 Sep 2020 04:55:09 -0400 Received: from localhost.localdomain (82-69-49-219.dsl.in-addr.zen.co.uk [82.69.49.219]) (Authenticated sender: tom) by mail.katalix.com (Postfix) with ESMTPSA id 5AE8D86C66; Thu, 3 Sep 2020 09:55:08 +0100 (BST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=katalix.com; s=mail; t=1599123308; bh=VEXEUb+/oqevL+R8UCQD7uxoPxCgimpGygm9z3+Pjms=; h=From:To:Cc:Subject:Date:Message-Id:In-Reply-To:References:From; z=From:=20Tom=20Parkin=20|To:=20netdev@vger.ke rnel.org|Cc:=20jchapman@katalix.com,=0D=0A=09Tom=20Parkin=20|Subject:=20[PATCH=20net-next=206/6]=20l2tp:=20avoi d=20duplicated=20code=20in=20l2tp_tunnel_closeall|Date:=20Thu,=20= 203=20Sep=202020=2009:54:52=20+0100|Message-Id:=20<20200903085452. 9487-7-tparkin@katalix.com>|In-Reply-To:=20<20200903085452.9487-1- tparkin@katalix.com>|References:=20<20200903085452.9487-1-tparkin@ katalix.com>; b=ORVNv6uQFXlPWEipAhuIGUXMb54XuU5RqfgWmEYgLsNEqj+AqWsBD2iIOpa6Jmq6H dXuWwQ1oNW/3GfEdoMhqSQMSkY68gLGwHbNB2bU2EuE9ZhRTJyY/+alwmrzNH/wEMS LnPmGrKDu84g3hKzaA8BCXSvnvHL/YiWK5S01o2RL+JidwzWyI+gzrn07MvJSiDwNI +nsjHO4CKA2qLMGYQ22ZID+bENB+mdR1iF/GpLDCEwWTKy1JhHK14Tdg7+uAzuCjOP 3+s/b7mAR1uKkwUWoxyR5qMOHb3Wnemm7c3CPI7udARmsLg9iyGFGkyZLGiN9RrxAw 8HJazh2RB6+Xw== From: Tom Parkin To: netdev@vger.kernel.org Cc: jchapman@katalix.com, Tom Parkin Subject: [PATCH net-next 6/6] l2tp: avoid duplicated code in l2tp_tunnel_closeall Date: Thu, 3 Sep 2020 09:54:52 +0100 Message-Id: <20200903085452.9487-7-tparkin@katalix.com> X-Mailer: git-send-email 2.17.1 In-Reply-To: <20200903085452.9487-1-tparkin@katalix.com> References: <20200903085452.9487-1-tparkin@katalix.com> Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org l2tp_tunnel_closeall is called as a part of tunnel shutdown in order to close all the sessions held by the tunnel. The code it uses to close a session duplicates what l2tp_session_delete does. Rather than duplicating the code, have l2tp_tunnel_closeall call l2tp_session_delete instead. This involves a very minor change to locking in l2tp_tunnel_closeall. Previously, l2tp_tunnel_closeall checked the session "dead" flag while holding tunnel->hlist_lock. This allowed for the code to step to the next session in the list without releasing the lock if the current session happened to be in the process of closing already. By calling l2tp_session_delete instead, l2tp_tunnel_closeall must now drop and regain the hlist lock for each session in the tunnel list. Given that the likelihood of a session being in the process of closing when the tunnel is closed, it seems worth this very minor potential loss of efficiency to avoid duplication of the session delete code. Signed-off-by: Tom Parkin --- net/l2tp/l2tp_core.c | 14 +------------- 1 file changed, 1 insertion(+), 13 deletions(-) diff --git a/net/l2tp/l2tp_core.c b/net/l2tp/l2tp_core.c index b02b3cc67df0..7de05be4fc33 100644 --- a/net/l2tp/l2tp_core.c +++ b/net/l2tp/l2tp_core.c @@ -1191,22 +1191,10 @@ static void l2tp_tunnel_closeall(struct l2tp_tunnel *tunnel) again: hlist_for_each_safe(walk, tmp, &tunnel->session_hlist[hash]) { session = hlist_entry(walk, struct l2tp_session, hlist); - hlist_del_init(&session->hlist); - if (test_and_set_bit(0, &session->dead)) - goto again; - write_unlock_bh(&tunnel->hlist_lock); - - l2tp_session_unhash(session); - l2tp_session_queue_purge(session); - - if (session->session_close) - (*session->session_close)(session); - - l2tp_session_dec_refcount(session); - + l2tp_session_delete(session); write_lock_bh(&tunnel->hlist_lock); /* Now restart from the beginning of this hash