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 32C8BC433FE for ; Sat, 30 Oct 2021 17:19:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1707260F9B for ; Sat, 30 Oct 2021 17:19:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230245AbhJ3RVi (ORCPT ); Sat, 30 Oct 2021 13:21:38 -0400 Received: from mail.kernel.org ([198.145.29.99]:41968 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230184AbhJ3RVY (ORCPT ); Sat, 30 Oct 2021 13:21:24 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 27DC561051; Sat, 30 Oct 2021 17:18:54 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1635614334; bh=QhluK+06FrJHkanlZMVBtEgZbu3hLUjKpRQYz7lJRRs=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=btpcjxA3OQjwUWeVVISP7T1/uVK0//jT4OAllJxkmIJyp/Z54KVTnRTTR5Wb1bDc3 TVlipsXSeZCZ4KIHwJtH2HzjYn7lbxn6Bkeylzjp7eVl9wU5WZafiGW9dcBTlg1jm/ /8kpIxGWrfsnNBWGqSQzP14nprJDnGu4W+El8+CFW0rSgew9snjWZ9qp7grW5jtII3 TrN3i66qcEQOSOAaz720j3K9O1u1nupQwqRxTyxZ3qm1IpD2iBxy5LQPeglC8ZtpN4 A/YSeCuBXQjsciSvlh/BeeWTQOTN2PFkxE5FltvAYUkWZiBE+KDgmvbex/funN3olG GalEYPBhCnesQ== From: Jakub Kicinski To: davem@davemloft.net Cc: netdev@vger.kernel.org, jiri@resnulli.us, leon@kernel.org, mkubecek@suse.cz, andrew@lunn.ch, f.fainelli@gmail.com, Jakub Kicinski Subject: [PATCH net-next v2 3/4] devlink: expose get/put functions Date: Sat, 30 Oct 2021 10:18:50 -0700 Message-Id: <20211030171851.1822583-4-kuba@kernel.org> X-Mailer: git-send-email 2.31.1 In-Reply-To: <20211030171851.1822583-1-kuba@kernel.org> References: <20211030171851.1822583-1-kuba@kernel.org> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org Allow those who hold implicit reference on a devlink instance to try to take a full ref on it. This will be used from netdev code which has an implicit ref because of driver call ordering. Note that after recent changes devlink_unregister() may happen before netdev unregister, but devlink_free() should still happen after, so we are safe to try, but we can't just refcount_inc() and assume it's not zero. Signed-off-by: Jakub Kicinski --- include/net/devlink.h | 12 ++++++++++++ net/core/devlink.c | 8 +++++--- 2 files changed, 17 insertions(+), 3 deletions(-) diff --git a/include/net/devlink.h b/include/net/devlink.h index 1b1317d378de..991ce48f77ca 100644 --- a/include/net/devlink.h +++ b/include/net/devlink.h @@ -1726,6 +1726,9 @@ devlink_trap_policers_unregister(struct devlink *devlink, #if IS_ENABLED(CONFIG_NET_DEVLINK) +struct devlink *__must_check devlink_try_get(struct devlink *devlink); +void devlink_put(struct devlink *devlink); + void devlink_compat_running_version(struct net_device *dev, char *buf, size_t len); int devlink_compat_flash_update(struct net_device *dev, const char *file_name); @@ -1736,6 +1739,15 @@ int devlink_compat_switch_id_get(struct net_device *dev, #else +static inline struct devlink *devlink_try_get(struct devlink *devlink) +{ + return NULL; +} + +static inline void devlink_put(struct devlink *devlink) +{ +} + static inline void devlink_compat_running_version(struct net_device *dev, char *buf, size_t len) { diff --git a/net/core/devlink.c b/net/core/devlink.c index 2d8abe88c673..100d87fd3f65 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -182,15 +182,17 @@ struct net *devlink_net(const struct devlink *devlink) } EXPORT_SYMBOL_GPL(devlink_net); -static void devlink_put(struct devlink *devlink) +void devlink_put(struct devlink *devlink) { if (refcount_dec_and_test(&devlink->refcount)) complete(&devlink->comp); } -static bool __must_check devlink_try_get(struct devlink *devlink) +struct devlink *__must_check devlink_try_get(struct devlink *devlink) { - return refcount_inc_not_zero(&devlink->refcount); + if (refcount_inc_not_zero(&devlink->refcount)) + return devlink; + return NULL; } static struct devlink *devlink_get_from_attrs(struct net *net, -- 2.31.1