From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932494AbcEQIPc (ORCPT ); Tue, 17 May 2016 04:15:32 -0400 Received: from mail-lb0-f178.google.com ([209.85.217.178]:35231 "EHLO mail-lb0-f178.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755370AbcEQIPX (ORCPT ); Tue, 17 May 2016 04:15:23 -0400 MIME-Version: 1.0 In-Reply-To: <20160517062829.GG14480@ZenIV.linux.org.uk> References: <87d1ombix6.fsf@gamma.ozlabs.ibm.com> <20160516130727.GA26411@redhat.com> <20160517062829.GG14480@ZenIV.linux.org.uk> Date: Tue, 17 May 2016 10:15:21 +0200 Message-ID: Subject: Re: 45aebeaf4f67 "ovl: Ensure upper filesystem supports d_type" breaking Docker From: Miklos Szeredi To: Al Viro Cc: Vivek Goyal , Daniel Axtens , linux-fsdevel , linux-unionfs@vger.kernel.org, linux-kernel@vger.kernel.org, mpe@ellerman.id.au, dchinner@redhat.com Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, May 17, 2016 at 8:28 AM, Al Viro wrote: > On Mon, May 16, 2016 at 09:07:27AM -0400, Vivek Goyal wrote: >> So it became clear that we need a check at mount time to make sure >> d_type is supported otherwise error out. This will require users to >> do mkfs.xfs with ftype=1 to make progress. >> >> I think new defaults for mkfs.xfs are such that ftype=1 is set. I am >> not sure which version that change was made in. > > Dumb question - can we end up with empty workdir at that point? Because > if we do, the check would appear to return a false negative, no matter > what fs supports... ovl_workdir_create() creates a subdirectory of workdir ("work") so workdir itself won't be empty after that. If somebody else messes with workdir, then we are screwed anyway. Thanks, Miklos