From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933024AbXCRWgN (ORCPT ); Sun, 18 Mar 2007 18:36:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932985AbXCRWgN (ORCPT ); Sun, 18 Mar 2007 18:36:13 -0400 Received: from ug-out-1314.google.com ([66.249.92.169]:62457 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933024AbXCRWgM (ORCPT ); Sun, 18 Mar 2007 18:36:12 -0400 Date: Mon, 19 Mar 2007 00:36:53 +0200 From: "Michael S. Tsirkin" To: "Eric W. Biederman" Cc: "Michael S. Tsirkin" , Alexey Kuznetsov , netdev@vger.kernel.org, Linux Kernel Mailing List , general@lists.openfabrics.org Subject: Re: [ofa-general] Re: dst_ifdown breaks infiniband? Message-ID: <20070318223653.GO11078@mellanox.co.il> Reply-To: "Michael S. Tsirkin" References: <20070318155532.GG7958@mellanox.co.il> <20070318191238.GA20518@ms2.inr.ac.ru> <20070318202559.GD11078@mellanox.co.il> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.11 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > Quoting Eric W. Biederman : > Subject: Re: [ofa-general] Re: dst_ifdown breaks infiniband? > > "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. Hmm. Then the code moving dst->dev to point to the loopback device will have to be fixed too. I'll post a patch a bit later. -- MST