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=-11.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED 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 55797C433B4 for ; Tue, 11 May 2021 03:57:26 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 28E23616EC for ; Tue, 11 May 2021 03:57:26 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229931AbhEKD6a (ORCPT ); Mon, 10 May 2021 23:58:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:37772 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230096AbhEKD60 (ORCPT ); Mon, 10 May 2021 23:58:26 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id A87B66191A; Tue, 11 May 2021 03:57:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1620705427; bh=KUxSfdHuT0OzxKcmushlCf+iiGLeisPcY+my+vMSNNA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=XA4NRg2XadNBSNYtby2zm8km5MLfULMiSS8oFp/rowdp1wF4KaICxoyLe0XOXlSLQ dAzqy1GaCwX0GXO2mQtRIgCFJbVNLR6YG7Wb51ID2ezfLw9ZU5D+E1UYmzTTiXU8/9 dK5oIlBZ9wzqFCsp9FvDDLJeD2klTKBCtqOOrg3ekFcl9rpQu95XyoyO3dT6b95LXA okn07Xswk7QRewU03CuFaHwqWV02X5zBRnJZi9i78mPhu9whxd2l7o6lOnQvlnRjkr Ksj2BOYzGH6Ji74D9XKC0tFZvmKUNgrxzOGqPYF6iadWOteVMQIeGHSerUCYeIeW+D GDTXwujDTFTMw== Date: Mon, 10 May 2021 20:57:06 -0700 From: "Darrick J. Wong" 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, viro@zeniv.linux.org.uk, david@fromorbit.com, hch@lst.de, rgoldwyn@suse.de Subject: Re: [PATCH v5 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax Message-ID: <20210511035706.GL8582@magnolia> References: <20210511030933.3080921-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210511030933.3080921-1-ruansy.fnst@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, May 11, 2021 at 11:09:26AM +0800, 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. Slightly off topic, but I noticed all my pmem disappeared once I rolled forward to 5.13-rc1. Am I the only lucky one? Qemu 4.2, with fake memory devices backed by tmpfs files -- info qtree says they're there, but the kernel doesn't show anything in /proc/iomem. --D > Changes from V4: > - Fix the mistake of breaking dax layout for two inodes > - Add CONFIG_FS_DAX judgement for fsdax code in remap_range.c > - Fix other small problems and mistakes > > Changes from V3: > - Take out the first 3 patches as a cleanup patchset[1], which has been > sent yesterday. > - Fix usage of code in dax_iomap_cow_copy() > - Add comments for macro definitions > - Fix other code style problems and mistakes > > 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 mechanisms 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. > > > (Rebased on v5.13-rc1 and patchset[1]) > [1]: https://lkml.org/lkml/2021/4/22/575 > > Shiyang Ruan (7): > fsdax: Introduce dax_iomap_cow_copy() > fsdax: Replace mmap entry in case of CoW > fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero > iomap: Introduce iomap_apply2() for operations on two files > fsdax: Dedup file range to use a compare function > fs/xfs: Handle CoW for fsdax write() path > fs/xfs: Add dax dedupe support > > fs/dax.c | 206 +++++++++++++++++++++++++++++++++++------ > fs/iomap/apply.c | 52 +++++++++++ > fs/iomap/buffered-io.c | 2 +- > fs/remap_range.c | 57 ++++++++++-- > fs/xfs/xfs_bmap_util.c | 3 +- > fs/xfs/xfs_file.c | 11 +-- > fs/xfs/xfs_inode.c | 66 ++++++++++++- > fs/xfs/xfs_inode.h | 1 + > fs/xfs/xfs_iomap.c | 61 +++++++++++- > fs/xfs/xfs_iomap.h | 4 + > fs/xfs/xfs_iops.c | 7 +- > fs/xfs/xfs_reflink.c | 15 +-- > include/linux/dax.h | 7 +- > include/linux/fs.h | 12 ++- > include/linux/iomap.h | 7 +- > 15 files changed, 449 insertions(+), 62 deletions(-) > > -- > 2.31.1 > > >