From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ignacy Gawedzki Subject: VLAN creation may lead to deadlock. Date: Fri, 13 Feb 2015 13:02:17 +0100 Message-ID: <20150213120217.GA6198@zenon.in.qult.net> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-2 Content-Transfer-Encoding: QUOTED-PRINTABLE To: netdev@vger.kernel.org Return-path: Received: from [78.193.33.39] ([78.193.33.39]:47772 "EHLO mail.qult.net" rhost-flags-FAIL-FAIL-OK-OK) by vger.kernel.org with ESMTP id S1752362AbbBMMDG (ORCPT ); Fri, 13 Feb 2015 07:03:06 -0500 Received: from zenon.in.qult.net ([192.168.64.1] helo=zenon) by mail.qult.net with esmtps (TLS1.2:RSA_AES_128_CBC_SHA1:128) (Exim 4.82) (envelope-from ) id 1YMExF-0002g3-V1 for netdev@vger.kernel.org; Fri, 13 Feb 2015 13:02:42 +0100 Received: from ig by zenon with local (Exim 4.84_RC1) (envelope-from ) id 1YMEwr-00024U-9I for netdev@vger.kernel.org; Fri, 13 Feb 2015 13:02:17 +0100 Content-Disposition: inline Sender: netdev-owner@vger.kernel.org List-ID: Hi, I stumbled upon the following annoying situation: supposing eth0 is som= e interface that is currently DOWN, the following command ip link add link eth0 name eth0.1 up type vlan id 1 never returns and the kernel printks the following lines every few seco= nds unregister_netdevice: waiting for eth0.1 to become free. Usage count = =3D 2 I understand that the kernel should prevent me from creating a VLAN int= erface that's initially up when loose-binding is off and the master interface = is down (and indeed there is absolutely no problem when loose-binding is on), b= ut the unregistering of the currently-being-registered device should not block= like that. It appears there are too few dev_puts compared to dev_holds in t= here. Regards, Ignacy --=20 Ignacy Gaw=EAdzki R&D Engineer Green Communications