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=-10.2 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,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 8335FC433E6 for ; Mon, 8 Feb 2021 15:41:49 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 3BCF264E50 for ; Mon, 8 Feb 2021 15:41:49 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234072AbhBHPlo (ORCPT ); Mon, 8 Feb 2021 10:41:44 -0500 Received: from mx2.suse.de ([195.135.220.15]:43186 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233887AbhBHPjy (ORCPT ); Mon, 8 Feb 2021 10:39:54 -0500 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.221.27]) by mx2.suse.de (Postfix) with ESMTP id 03D05ADDD; Mon, 8 Feb 2021 15:39:12 +0000 (UTC) Received: by quack2.suse.cz (Postfix, from userid 1000) id AD8FD1E13F9; Mon, 8 Feb 2021 16:39:11 +0100 (CET) Date: Mon, 8 Feb 2021 16:39:11 +0100 From: Jan Kara To: Shiyang Ruan Cc: linux-kernel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-nvdimm@lists.01.org, linux-fsdevel@vger.kernel.org, darrick.wong@oracle.com, dan.j.williams@intel.com, willy@infradead.org, jack@suse.cz, viro@zeniv.linux.org.uk, linux-btrfs@vger.kernel.org, ocfs2-devel@oss.oracle.com, david@fromorbit.com, hch@lst.de, rgoldwyn@suse.de Subject: Re: [PATCH 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax Message-ID: <20210208153911.GE30081@quack2.suse.cz> References: <20210207170924.2933035-1-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210207170924.2933035-1-ruansy.fnst@cn.fujitsu.com> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon 08-02-21 01:09:17, Shiyang Ruan wrote: > This patchset is attempt to add CoW support for fsdax, and take XFS, > which has both reflink and fsdax feature, as an example. > > One of the key mechanism need to be implemented in fsdax is CoW. Copy > the data from srcmap before we actually write data to the destance > iomap. And we just copy range in which data won't be changed. > > Another mechanism is range comparison . In page cache case, readpage() > is used to load data on disk to page cache in order to be able to > compare data. In fsdax case, readpage() does not work. So, we need > another compare data with direct access support. > > With the two mechanism implemented in fsdax, we are able to make reflink > and fsdax work together in XFS. > > Some of the patches are picked up from Goldwyn's patchset. I made some > changes to adapt to this patchset. How do you deal with HWPoison code trying to reverse-map struct page back to inode-offset pair? This also needs to be fixed for reflink to work with DAX. Honza > > (Rebased on v5.10) > == > > Shiyang Ruan (7): > fsdax: Output address in dax_iomap_pfn() and rename it > fsdax: Introduce dax_copy_edges() for CoW > fsdax: Copy data before write > fsdax: Replace mmap entry in case of CoW > fsdax: Dedup file range to use a compare function > fs/xfs: Handle CoW for fsdax write() path > fs/xfs: Add dedupe support for fsdax > > fs/btrfs/reflink.c | 3 +- > fs/dax.c | 188 ++++++++++++++++++++++++++++++++++++++--- > fs/ocfs2/file.c | 2 +- > fs/remap_range.c | 14 +-- > fs/xfs/xfs_bmap_util.c | 6 +- > fs/xfs/xfs_file.c | 30 ++++++- > fs/xfs/xfs_inode.c | 8 +- > fs/xfs/xfs_inode.h | 1 + > fs/xfs/xfs_iomap.c | 3 +- > fs/xfs/xfs_iops.c | 11 ++- > fs/xfs/xfs_reflink.c | 23 ++++- > include/linux/dax.h | 5 ++ > include/linux/fs.h | 9 +- > 13 files changed, 270 insertions(+), 33 deletions(-) > > -- > 2.30.0 > > > -- Jan Kara SUSE Labs, CR