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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, URIBL_BLOCKED,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 C7015C2BB85 for ; Wed, 15 Apr 2020 08:24:11 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id ACE1820775 for ; Wed, 15 Apr 2020 08:24:11 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2894424AbgDOIYG (ORCPT ); Wed, 15 Apr 2020 04:24:06 -0400 Received: from mx2.suse.de ([195.135.220.15]:56378 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2894396AbgDOIYA (ORCPT ); Wed, 15 Apr 2020 04:24:00 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx2.suse.de (Postfix) with ESMTP id 4F2E3AD57; Wed, 15 Apr 2020 08:23:57 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id 2D7991E0E47; Wed, 15 Apr 2020 10:23:57 +0200 (CEST) Date: Wed, 15 Apr 2020 10:23:57 +0200 From: Jan Kara To: Ira Weiny Cc: Dan Williams , "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: <20200415082357.GC501@quack2.suse.cz> 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> <20200414194848.GD1853609@iweiny-DESK2.sc.intel.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200414194848.GD1853609@iweiny-DESK2.sc.intel.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org On Tue 14-04-20 12:48:48, Ira Weiny wrote: > 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. I'm fine with that. I wouldn't really bother with per-inode DAX flag for ext2. Honza -- Jan Kara SUSE Labs, CR