From mboxrd@z Thu Jan 1 00:00:00 1970 From: Mike Snitzer Subject: Re: 2.6.35 causes deadlock when snapshotting root lv Date: Thu, 17 Jun 2010 10:27:32 -0400 Message-ID: <20100617142731.GA10071@redhat.com> References: <4C1A2839.5010407@cfl.rr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: device-mapper development , linux-fsdevel@vger.kernel.org To: Phillip Susi Return-path: Received: from mx1.redhat.com ([209.132.183.28]:18280 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760099Ab0FQO1m (ORCPT ); Thu, 17 Jun 2010 10:27:42 -0400 Content-Disposition: inline In-Reply-To: <4C1A2839.5010407@cfl.rr.com> Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Jun 17 2010 at 9:50am -0400, Phillip Susi wrote: > What: > > lvcreate -s -n snap -L 1g vg/root hangs in an unkillable state while > trying to flush the fs and suspend the device to switch tables over to > the snapshot, and no further IO is possible so the system must be hard > booted with magic-sysrq. > > Where: 2.6.35, all 3 release candidates. 2.6.34 and earlier kernels are > fine. Which filesystem are you using? Which 2.6.35-rc? There haven't been _any_ changes to DM for 2.6.35 (some DM fixes may get pushed to Linus once Alasdair gets back from traveling). So what this means is that the VFS (or ext4) freeze changes introduced in 2.6.35 are the likely culprit: http://git.kernel.org/linus/18e9e5104fcd9a9 http://git.kernel.org/linus/6b0310fbf087ad6 Though it could also be an issue with the various 2.6.35 writeback changes (depending on which -rcX you're using). Point is: this is not a DM regression. Mike