Return-Path: linux-nfs-owner@vger.kernel.org Received: from fieldses.org ([174.143.236.118]:55459 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754523Ab3C1Sb6 (ORCPT ); Thu, 28 Mar 2013 14:31:58 -0400 Date: Thu, 28 Mar 2013 14:31:53 -0400 From: "J. Bruce Fields" To: Anand Avati Cc: Zach Brown , "Theodore Ts'o" , Eric Sandeen , Bernd Schubert , linux-nfs@vger.kernel.org, linux-ext4@vger.kernel.org, gluster-devel@nongnu.org Subject: Re: [Gluster-devel] regressions due to 64-bit ext4 directory cookies Message-ID: <20130328183153.GG7080@fieldses.org> References: <20130213224720.GE5938@thunk.org> <20130213230511.GW14195@fieldses.org> <20130213234430.GF5938@thunk.org> <5151BD5F.30607@itwm.fraunhofer.de> <5151C33E.2070008@redhat.com> <20130328140744.GA4989@thunk.org> <20130328175205.GD16651@lenny.home.zabbo.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, Mar 28, 2013 at 11:05:41AM -0700, Anand Avati wrote: > On Thu, Mar 28, 2013 at 10:52 AM, Zach Brown wrote: > > > On Thu, Mar 28, 2013 at 10:07:44AM -0400, Theodore Ts'o wrote: > > > On Tue, Mar 26, 2013 at 10:48:14AM -0500, Eric Sandeen wrote: > > > > > We don't have reached a conclusion so far, do we? What about the > > > > > ioctl approach, but a bit differently? Would it work to specify the > > > > > allowed upper bits for ext4 (for example 16 additional bit) and the > > > > > remaining part for gluster? One of the mails had the calculation > > > > > formula: > > > > > > > > I did throw together an ioctl patch last week, but I think Anand has a > > new > > > > approach he's trying out which won't require ext4 code changes. I'll > > let > > > > him reply when he has a moment. :) > > > > > > Any update about whether Gluster can address this without needing the > > > ioctl patch? Or should we push the ioctl patch into ext4 for the next > > > merge window? > > > > They're testing a work-around: > > > > http://review.gluster.org/#change,4711 > > > > I'm not sure if they've decided that they're going to go with it, or > > not. > > > > Jeff reported that the approach did not work in his testing. I haven't had > a chance to look into the failure yet. Independent of the fix, it would > certainly be good have the ioctl() support The one advantage of your scheme is that it keeps more of the hash bits; the chance of 31-bit cookie collisions is much higher. > Samba could use it too, if it wanted. It'd be useful to understand their situation. --b.