From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kirill Tkhai Subject: [PATCH RESEND net-next 0/2] net_rwsem fixes Date: Fri, 30 Mar 2018 19:38:16 +0300 Message-ID: <152242784495.18864.4373352355749698367.stgit@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: davem@davemloft.net, zhangshengju@cmss.chinamobile.com, ktkhai@virtuozzo.com, jakub.kicinski@netronome.com, dsahern@gmail.com, mschiffer@universe-factory.net, daniel@iogearbox.net, netdev@vger.kernel.org Return-path: Received: from mail-db5eur01on0134.outbound.protection.outlook.com ([104.47.2.134]:64576 "EHLO EUR01-DB5-obe.outbound.protection.outlook.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1751932AbeC3Qi0 (ORCPT ); Fri, 30 Mar 2018 12:38:26 -0400 Sender: netdev-owner@vger.kernel.org List-ID: (Forgot to CC netdev@ :) Hi, there is wext_netdev_notifier_call()->wireless_nlevent_flush() netdevice notifier, which takes net_rwsem, so we can't take net_rwsem in {,un}register_netdevice_notifier(). Since {,un}register_netdevice_notifier() is executed under pernet_ops_rwsem, net_namespace_list can't change, while we holding it, so there is no need net_rwsem in these functions [1/2]. The same is in [2/2]. We make callers of __rtnl_link_unregister() take pernet_ops_rwsem, and close the race with setup_net() and cleanup_net(), so __rtnl_link_unregister() does not need it. This also fixes the problem of that __rtnl_link_unregister() does not see initializing and exiting nets. Thanks, Kirill --- Kirill Tkhai (2): net: Remove net_rwsem from {,un}register_netdevice_notifier() net: Do not take net_rwsem in __rtnl_link_unregister() drivers/net/dummy.c | 2 ++ drivers/net/ifb.c | 2 ++ net/core/dev.c | 5 ----- net/core/net_namespace.c | 1 + net/core/rtnetlink.c | 6 +++--- 5 files changed, 8 insertions(+), 8 deletions(-)