From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S965044AbXCSAZl (ORCPT ); Sun, 18 Mar 2007 20:25:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S965034AbXCSAZl (ORCPT ); Sun, 18 Mar 2007 20:25:41 -0400 Received: from zoot.lnxi.com ([63.145.151.20]:44862 "EHLO zoot.lnxi.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S964974AbXCSAZj (ORCPT ); Sun, 18 Mar 2007 20:25:39 -0400 X-Greylist: delayed 7267 seconds by postgrey-1.27 at vger.kernel.org; Sun, 18 Mar 2007 20:25:39 EDT To: "Michael S. Tsirkin" Cc: Alexey Kuznetsov , netdev@vger.kernel.org, Linux Kernel Mailing List , general@lists.openfabrics.org Subject: Re: [ofa-general] Re: dst_ifdown breaks infiniband? References: <20070318155532.GG7958@mellanox.co.il> <20070318191238.GA20518@ms2.inr.ac.ru> <20070318202559.GD11078@mellanox.co.il> From: ebiederman@lnxi.com (Eric W. Biederman) Date: Sun, 18 Mar 2007 16:24:23 -0600 In-Reply-To: <20070318202559.GD11078@mellanox.co.il> (Michael S. Tsirkin's message of "Sun, 18 Mar 2007 22:25:59 +0200") Message-ID: User-Agent: Gnus/5.1007 (Gnus v5.10.7) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org "Michael S. Tsirkin" writes: >> > Why is neighbour->dev changed here? >> >> It holds reference to device and prevents its destruction. >> If dst is held somewhere, we cannot destroy the device and deadlock >> while unregister. > > BTW, can this ever happen for the loopback device itself? > Is it ever unregistered? Well I don't think the loopback device is currently but as soon as we get network namespace support we will have multiple loopback devices and they will get unregistered when we remove the network namespace. Eric