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=-8.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=unavailable 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 27E99C2BB1D for ; Tue, 14 Apr 2020 19:50:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 0BD60206E9 for ; Tue, 14 Apr 2020 19:50:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730249AbgDNTuq (ORCPT ); Tue, 14 Apr 2020 15:50:46 -0400 Received: from mga03.intel.com ([134.134.136.65]:47138 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2505188AbgDNTst (ORCPT ); Tue, 14 Apr 2020 15:48:49 -0400 IronPort-SDR: Fzz8nA7FwzUXByu/1QJRb0mCQ7Hpm6ynkr/+OcfzwI3BgArq4mu9PG1tom98rkcvlb7l30Nujh EOrsKGlgQEVg== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga008.fm.intel.com ([10.253.24.58]) by orsmga103.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 14 Apr 2020 12:48:48 -0700 IronPort-SDR: /9PXD6UyYfnTEnbuhi6ZiIjqDVppnyJ2nPEU9AuDspmduyNhwdFw8pICveKs/c+tIj7vTxfy4A HF7rEguRJHCA== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.72,384,1580803200"; d="scan'208";a="245504497" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by fmsmga008.fm.intel.com with ESMTP; 14 Apr 2020 12:48:48 -0700 Date: Tue, 14 Apr 2020 12:48:48 -0700 From: Ira Weiny To: Dan Williams Cc: "Darrick J. Wong" , Linux Kernel Mailing List , Dave Chinner , Christoph Hellwig , "Theodore Y. Ts'o" , Jan Kara , Jeff Moyer , linux-ext4 , linux-xfs , linux-fsdevel Subject: Re: [PATCH V7 9/9] Documentation/dax: Update Usage section Message-ID: <20200414194848.GD1853609@iweiny-DESK2.sc.intel.com> References: <20200413054046.1560106-1-ira.weiny@intel.com> <20200413054046.1560106-10-ira.weiny@intel.com> <20200413161912.GZ6742@magnolia> <20200414043821.GG1649878@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.11.1 (2018-12-01) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Apr 13, 2020 at 10:12:22PM -0700, Dan Williams wrote: > On Mon, Apr 13, 2020 at 9:38 PM Ira Weiny wrote: > > > > On Mon, Apr 13, 2020 at 09:19:12AM -0700, Darrick J. Wong wrote: > > > On Sun, Apr 12, 2020 at 10:40:46PM -0700, ira.weiny@intel.com wrote: > > > > From: Ira Weiny > > > > > > > > Update the Usage section to reflect the new individual dax selection > > > > functionality. > > > > > > Yum. :) > > > > > > > Signed-off-by: Ira Weiny > > > > > > > > --- > > > > Changes from V6: > > > > Update to allow setting FS_XFLAG_DAX any time. > > > > Update with list of behaviors from Darrick > > > > https://lore.kernel.org/lkml/20200409165927.GD6741@magnolia/ > > > > > > > > Changes from V5: > > > > Update to reflect the agreed upon semantics > > > > https://lore.kernel.org/lkml/20200405061945.GA94792@iweiny-DESK2.sc.intel.com/ > > > > --- > > > > Documentation/filesystems/dax.txt | 166 +++++++++++++++++++++++++++++- > > > > 1 file changed, 163 insertions(+), 3 deletions(-) > > > > > > > > diff --git a/Documentation/filesystems/dax.txt b/Documentation/filesystems/dax.txt > > > > index 679729442fd2..af14c1b330a9 100644 > > > > --- a/Documentation/filesystems/dax.txt > > > > +++ b/Documentation/filesystems/dax.txt > > > > @@ -17,11 +17,171 @@ For file mappings, the storage device is mapped directly into userspace. > > > > Usage > > > > ----- > > > > > > > > -If you have a block device which supports DAX, you can make a filesystem > > > > +If you have a block device which supports DAX, you can make a file system > > > > on it as usual. The DAX code currently only supports files with a block > > > > size equal to your kernel's PAGE_SIZE, so you may need to specify a block > > > > -size when creating the filesystem. When mounting it, use the "-o dax" > > > > -option on the command line or add 'dax' to the options in /etc/fstab. > > > > +size when creating the file system. > > > > + > > > > +Currently 2 filesystems support DAX, ext4 and xfs. Enabling DAX on them is > > > > +different at this time. > > > > > > I thought ext2 supports DAX? > > > > Not that I know of? Does it? > > Yes. Seemed like a good idea at the time, but in retrospect... Ah ok... Is there an objection to leaving ext2 as a global mount option? Updating the doc is easy enough. Ira > > In fairness I believe this was also an olive branch to XIP users that > were transitioned to DAX, so they did not also need to transition > filesystems.