From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from ipmail07.adl2.internode.on.net ([150.101.137.131]:57339 "EHLO ipmail07.adl2.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753096AbcA2WUW (ORCPT ); Fri, 29 Jan 2016 17:20:22 -0500 Date: Sat, 30 Jan 2016 09:20:06 +1100 From: Dave Chinner To: Dan Williams Cc: XFS Developers , linux-fsdevel , ext4@vger.kernel.org, Matthew Wilcox Subject: Re: [PATCH 3/3] xfs: introduce per-inode DAX enablement Message-ID: <20160129222006.GJ20456@dastard> References: <1451886892-15548-1-git-send-email-david@fromorbit.com> <1451886892-15548-4-git-send-email-david@fromorbit.com> <20160121215820.GA6033@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Jan 21, 2016 at 02:53:06PM -0800, Dan Williams wrote: > On Thu, Jan 21, 2016 at 1:58 PM, Dave Chinner wrote: > > On Thu, Jan 21, 2016 at 08:37:11AM -0800, Dan Williams wrote: > >> On Sun, Jan 3, 2016 at 9:54 PM, Dave Chinner wrote: > > i.e. I've already got a couple of fixes we need to add to this - the > > DAX flag is only valid on CRC enabled filesystems, > > I assume for torn-write protection? The CRC limitation makes sense, > but we theoretically could get the same effect by using a separate > logdev that does not tear writes, right? No, it requires the CRC enabled format because there isn't any flag space left in the v2 inode and so we need v3 inodes to store the flag. Cheers, Dave. -- Dave Chinner david@fromorbit.com