From patchwork Sun Aug 29 12:25:10 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Shiyang Ruan X-Patchwork-Id: 12463885 Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by smtp.subspace.kernel.org (Postfix) with ESMTP id 727893FC1 for ; Sun, 29 Aug 2021 12:25:42 +0000 (UTC) IronPort-HdrOrdr: A9a23:htUtwa27tAqbjRTnawv0fAqjBI4kLtp133Aq2lEZdPU1SL39qynKppkmPHDP5gr5J0tLpTntAsi9qBDnhPtICOsqTNSftWDd0QPGEGgI1/qB/9SPIU3D398Y/aJhXow7M9foEGV95PyQ3CCIV/om3/mLmZrFudvj X-IronPort-AV: E=Sophos;i="5.84,361,1620662400"; d="scan'208";a="113656446" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 29 Aug 2021 20:25:31 +0800 Received: from G08CNEXMBPEKD04.g08.fujitsu.local (unknown [10.167.33.201]) by cn.fujitsu.com (Postfix) with ESMTP id 6759A4D0D4A1; Sun, 29 Aug 2021 20:25:27 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD04.g08.fujitsu.local (10.167.33.201) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Sun, 29 Aug 2021 20:25:23 +0800 Received: from irides.mr.mr.mr (10.167.225.141) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Sun, 29 Aug 2021 20:25:21 +0800 From: Shiyang Ruan To: , , CC: , , , , , , , , Subject: [PATCH v8 0/7] fsdax,xfs: Add reflink&dedupe support for fsdax Date: Sun, 29 Aug 2021 20:25:10 +0800 Message-ID: <20210829122517.1648171-1-ruansy.fnst@fujitsu.com> X-Mailer: git-send-email 2.32.0 Precedence: bulk X-Mailing-List: nvdimm@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 X-yoursite-MailScanner-ID: 6759A4D0D4A1.A01A4 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Spam-Status: No This patchset is attempt to add CoW support for fsdax, and take XFS, which has both reflink and fsdax feature, as an example. Changes from V7: - Patch 3: Update to iter model[1] - Patch 4: Add the missing memset() in CoW case - Remove iomap_iter2(), use 2 nested iomap_iter() instead - Patch 6: Remove dax_iomap_ops, handle end CoW operations in ->iomap_end() - Update docs, comments 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. (Rebased on v5.14-rc4 and Christoph's "switch iomap to an iterator model v2"[1]) [1]: https://lore.kernel.org/linux-xfs/20210809061244.1196573-1-hch@lst.de/ == Shiyang Ruan (7): fsdax: Output address in dax_iomap_pfn() and rename it fsdax: Introduce dax_iomap_cow_copy() fsdax: Replace mmap entry in case of CoW fsdax: Add dax_iomap_cow_copy() for dax_iomap_zero fsdax: Dedup file range to use a compare function xfs: support CoW in fsdax mode xfs: Add dax dedupe support fs/dax.c | 319 ++++++++++++++++++++++++++++++++++------- fs/iomap/buffered-io.c | 7 +- fs/remap_range.c | 39 +++-- fs/xfs/xfs_bmap_util.c | 3 +- fs/xfs/xfs_file.c | 6 +- fs/xfs/xfs_inode.c | 57 ++++++++ fs/xfs/xfs_inode.h | 1 + fs/xfs/xfs_iomap.c | 32 ++++- fs/xfs/xfs_iomap.h | 32 +++++ fs/xfs/xfs_iops.c | 7 +- fs/xfs/xfs_reflink.c | 15 +- include/linux/dax.h | 15 +- include/linux/fs.h | 12 +- include/linux/iomap.h | 1 + 14 files changed, 460 insertions(+), 86 deletions(-)