From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 9FAD4C352A4 for ; Wed, 12 Feb 2020 16:10:47 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 80A8F20873 for ; Wed, 12 Feb 2020 16:10:47 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727669AbgBLQKn (ORCPT ); Wed, 12 Feb 2020 11:10:43 -0500 Received: from mga01.intel.com ([192.55.52.88]:30528 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726351AbgBLQKn (ORCPT ); Wed, 12 Feb 2020 11:10:43 -0500 X-Amp-Result: UNKNOWN X-Amp-Original-Verdict: FILE UNKNOWN X-Amp-File-Uploaded: False Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by fmsmga101.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 12 Feb 2020 08:10:42 -0800 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.70,433,1574150400"; d="scan'208";a="266718994" Received: from iweiny-desk2.sc.intel.com ([10.3.52.157]) by fmsmga002.fm.intel.com with ESMTP; 12 Feb 2020 08:10:41 -0800 Date: Wed, 12 Feb 2020 08:10:42 -0800 From: Ira Weiny To: Dave Chinner Cc: linux-kernel@vger.kernel.org, Alexander Viro , "Darrick J. Wong" , Dan Williams , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org Subject: Re: [PATCH v3 06/12] fs/xfs: Check if the inode supports DAX under lock Message-ID: <20200212161041.GE20214@iweiny-DESK2.sc.intel.com> References: <20200208193445.27421-1-ira.weiny@intel.com> <20200208193445.27421-7-ira.weiny@intel.com> <20200211061639.GH10776@dread.disaster.area> <20200211175509.GD12866@iweiny-DESK2.sc.intel.com> <20200211204220.GN10776@dread.disaster.area> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200211204220.GN10776@dread.disaster.area> User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Wed, Feb 12, 2020 at 07:42:20AM +1100, Dave Chinner wrote: > On Tue, Feb 11, 2020 at 09:55:09AM -0800, Ira Weiny wrote: > > On Tue, Feb 11, 2020 at 05:16:39PM +1100, Dave Chinner wrote: > > > On Sat, Feb 08, 2020 at 11:34:39AM -0800, ira.weiny@intel.com wrote: > > > > From: Ira Weiny > > > > [snip] > > > > > > This raciness in checking the DAX flags is the reason that > > > xfs_ioctl_setattr_xflags() redoes all the reflink vs dax checks once > > > it's called under the XFS_ILOCK_EXCL during the actual change > > > transaction.... > > > > Ok I found this by trying to make sure that the xfs_inode_supports_dax() call > > was always returning valid data. So I don't have a specific test which was > > failing. > > > > Looking at the code again, it sounds like I was wrong about which locks protect > > what and with your explanation above it looks like there is nothing to be done > > here and I can drop the patch. > > > > Would you agree? > > *nod* Thanks! done. Ira > > Cheers, > > Dave. > -- > Dave Chinner > david@fromorbit.com