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=-12.3 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PULL_REQUEST,MAILING_LIST_MULTI, MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=ham 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 19BE2C433DF for ; Tue, 2 Jun 2020 23:53:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id F1ED5206CD for ; Tue, 2 Jun 2020 23:53:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728414AbgFBXxH (ORCPT ); Tue, 2 Jun 2020 19:53:07 -0400 Received: from mga06.intel.com ([134.134.136.31]:39746 "EHLO mga06.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726267AbgFBXxG (ORCPT ); Tue, 2 Jun 2020 19:53:06 -0400 IronPort-SDR: 7pjoj0cj35/NaofwcrKVBE2fBmelzHAFVEgDiJ8cl6I5MsEB2nyJmoukJZqm9j3kZHlA9MHEzi nV/4PWozqlHw== X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from fmsmga005.fm.intel.com ([10.253.24.32]) by orsmga104.jf.intel.com with ESMTP/TLS/ECDHE-RSA-AES256-GCM-SHA384; 02 Jun 2020 16:53:05 -0700 IronPort-SDR: Fjosrr6vpGK5zwtIgnd84lq7g7jGjKCKBVDcWW2Xd9/i/a+bCVJiomnAZSEIQRGn0f9UiyeC0t kX8qGrZdgA4A== X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.73,466,1583222400"; d="scan'208";a="470925223" Received: from iweiny-desk2.sc.intel.com ([10.3.52.147]) by fmsmga005.fm.intel.com with ESMTP; 02 Jun 2020 16:53:05 -0700 Date: Tue, 2 Jun 2020 16:53:05 -0700 From: Ira Weiny To: "Darrick J. Wong" Cc: Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, david@fromorbit.com, linux-kernel@vger.kernel.org, sandeen@sandeen.net, hch@lst.de, linux-ext4 , Theodore Ts'o Subject: Re: [GIT PULL] vfs: improve DAX behavior for 5.8, part 1 Message-ID: <20200602235305.GI1505637@iweiny-DESK2.sc.intel.com> References: <20200602165852.GB8230@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200602165852.GB8230@magnolia> 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 Tue, Jun 02, 2020 at 09:58:52AM -0700, Darrick J. Wong wrote: > Hi Linus, > > After many years of LKML-wrangling about how to enable programs to query > and influence the file data access mode (DAX) when a filesystem resides > on storage devices such as persistent memory, Ira Weiny has emerged with > a proposed set of standard behaviors that has not been shot down by > anyone! We're more or less standardizing on the current XFS behavior > and adapting ext4 to do the same. Also, for those interested: The corresponding man page change mentioned in the commit has been submitted here: https://lore.kernel.org/lkml/20200505002016.1085071-1-ira.weiny@intel.com/ Ira > > This pull request is the first of a handful that will make ext4 and XFS > present a consistent interface for user programs that care about DAX. > We add a statx attribute that programs can check to see if DAX is > enabled on a particular file. Then, we update the DAX documentation to > spell out the user-visible behaviors that filesystems will guarantee > (until the next storage industry shakeup). The on-disk inode flag has > been in XFS for a few years now. > > Note that Stephen Rothwell reported a minor merge conflict[1] between > the first cleanup patch and a different change in the block layer. The > resolution looks pretty straightforward, but let me know if you > encounter problems. > > --D > > [1] https://lore.kernel.org/linux-next/20200522145848.38cdcf54@canb.auug.org.au/ > > The following changes since commit 0e698dfa282211e414076f9dc7e83c1c288314fd: > > Linux 5.7-rc4 (2020-05-03 14:56:04 -0700) > > are available in the Git repository at: > > git://git.kernel.org/pub/scm/fs/xfs/xfs-linux.git tags/vfs-5.8-merge-1 > > for you to fetch changes up to 83d9088659e8f113741bb197324bd9554d159657: > > Documentation/dax: Update Usage section (2020-05-04 08:49:39 -0700) > > ---------------------------------------------------------------- > New code for 5.8: > - Clean up io_is_direct. > - Add a new statx flag to indicate when file data access is being done > via DAX (as opposed to the page cache). > - Update the documentation for how system administrators and application > programmers can take advantage of the (still experimental DAX) feature. > > ---------------------------------------------------------------- > Ira Weiny (3): > fs: Remove unneeded IS_DAX() check in io_is_direct() > fs/stat: Define DAX statx attribute > Documentation/dax: Update Usage section > > Documentation/filesystems/dax.txt | 142 +++++++++++++++++++++++++++++++++++++- > drivers/block/loop.c | 6 +- > fs/stat.c | 3 + > include/linux/fs.h | 7 +- > include/uapi/linux/stat.h | 1 + > 5 files changed, 147 insertions(+), 12 deletions(-)