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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,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 4AC53C433DB for ; Fri, 1 Jan 2021 03:50:33 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 08AB22151B for ; Fri, 1 Jan 2021 03:50:32 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726942AbhAADuM (ORCPT ); Thu, 31 Dec 2020 22:50:12 -0500 Received: from smtp.h3c.com ([60.191.123.50]:17289 "EHLO h3cspam02-ex.h3c.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726583AbhAADuL (ORCPT ); Thu, 31 Dec 2020 22:50:11 -0500 Received: from DAG2EX08-IDC.srv.huawei-3com.com ([10.8.0.71]) by h3cspam02-ex.h3c.com with ESMTP id 1013lxAF085853; Fri, 1 Jan 2021 11:47:59 +0800 (GMT-8) (envelope-from gao.yanB@h3c.com) Received: from localhost.localdomain (10.99.212.201) by DAG2EX08-IDC.srv.huawei-3com.com (10.8.0.71) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256) id 15.1.2106.2; Fri, 1 Jan 2021 11:48:00 +0800 From: Gao Yan To: , , , , , CC: Gao Yan Subject: [PATCH] [v2]net:ppp: remove disc_data_lock in ppp line discipline Date: Fri, 1 Jan 2021 11:37:18 +0800 Message-ID: <20210101033718.45198-1-gao.yanB@h3c.com> X-Mailer: git-send-email 2.17.1 MIME-Version: 1.0 Content-Type: text/plain X-Originating-IP: [10.99.212.201] X-ClientProxiedBy: BJSMTP01-EX.srv.huawei-3com.com (10.63.20.132) To DAG2EX08-IDC.srv.huawei-3com.com (10.8.0.71) X-DNSRBL: X-MAIL: h3cspam02-ex.h3c.com 1013lxAF085853 Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In tty layer, it provides tty->ldisc_sem to protect all tty_ldisc_ops including ppp_sync_ldisc. So I think tty->ldisc_sem can also protect tty->disc_data, and the disc_data_lock is not necessary. Signed-off-by: Gao Yan --- drivers/net/ppp/ppp_async.c | 11 ++--------- drivers/net/ppp/ppp_synctty.c | 12 ++---------- 2 files changed, 4 insertions(+), 19 deletions(-) diff --git a/drivers/net/ppp/ppp_async.c b/drivers/net/ppp/ppp_async.c index 29a0917a8..20b50facd 100644 --- a/drivers/net/ppp/ppp_async.c +++ b/drivers/net/ppp/ppp_async.c @@ -127,17 +127,13 @@ static const struct ppp_channel_ops async_ops = { * FIXME: this is no longer true. The _close path for the ldisc is * now guaranteed to be sane. */ -static DEFINE_RWLOCK(disc_data_lock); static struct asyncppp *ap_get(struct tty_struct *tty) { - struct asyncppp *ap; + struct asyncppp *ap = tty->disc_data; - read_lock(&disc_data_lock); - ap = tty->disc_data; if (ap != NULL) refcount_inc(&ap->refcnt); - read_unlock(&disc_data_lock); return ap; } @@ -214,12 +210,9 @@ ppp_asynctty_open(struct tty_struct *tty) static void ppp_asynctty_close(struct tty_struct *tty) { - struct asyncppp *ap; + struct asyncppp *ap = tty->disc_data; - write_lock_irq(&disc_data_lock); - ap = tty->disc_data; tty->disc_data = NULL; - write_unlock_irq(&disc_data_lock); if (!ap) return; diff --git a/drivers/net/ppp/ppp_synctty.c b/drivers/net/ppp/ppp_synctty.c index 0f338752c..53fb68e29 100644 --- a/drivers/net/ppp/ppp_synctty.c +++ b/drivers/net/ppp/ppp_synctty.c @@ -129,17 +129,12 @@ ppp_print_buffer (const char *name, const __u8 *buf, int count) * * FIXME: Fixed in tty_io nowadays. */ -static DEFINE_RWLOCK(disc_data_lock); - static struct syncppp *sp_get(struct tty_struct *tty) { - struct syncppp *ap; + struct syncppp *ap = tty->disc_data; - read_lock(&disc_data_lock); - ap = tty->disc_data; if (ap != NULL) refcount_inc(&ap->refcnt); - read_unlock(&disc_data_lock); return ap; } @@ -213,12 +208,9 @@ ppp_sync_open(struct tty_struct *tty) static void ppp_sync_close(struct tty_struct *tty) { - struct syncppp *ap; + struct syncppp *ap = tty->disc_data; - write_lock_irq(&disc_data_lock); - ap = tty->disc_data; tty->disc_data = NULL; - write_unlock_irq(&disc_data_lock); if (!ap) return; -- 2.17.1