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=-5.3 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 C1E12C433DB for ; Mon, 8 Feb 2021 15:25:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7D64C64DDB for ; Mon, 8 Feb 2021 15:25:01 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233558AbhBHPYr (ORCPT ); Mon, 8 Feb 2021 10:24:47 -0500 Received: from verein.lst.de ([213.95.11.211]:41777 "EHLO verein.lst.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233681AbhBHPUF (ORCPT ); Mon, 8 Feb 2021 10:20:05 -0500 Received: by verein.lst.de (Postfix, from userid 2407) id B592868AFE; Mon, 8 Feb 2021 16:19:20 +0100 (CET) Date: Mon, 8 Feb 2021 16:19:20 +0100 From: Christoph Hellwig 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, Goldwyn Rodrigues Subject: Re: [PATCH 5/7] fsdax: Dedup file range to use a compare function Message-ID: <20210208151920.GE12872@lst.de> References: <20210207170924.2933035-1-ruansy.fnst@cn.fujitsu.com> <20210207170924.2933035-6-ruansy.fnst@cn.fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210207170924.2933035-6-ruansy.fnst@cn.fujitsu.com> User-Agent: Mutt/1.5.17 (2007-11-01) Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Mon, Feb 08, 2021 at 01:09:22AM +0800, Shiyang Ruan wrote: > With dax we cannot deal with readpage() etc. So, we create a > funciton callback to perform the file data comparison and pass s/funciton/function/g > +#define MIN(a, b) (((a) < (b)) ? (a) : (b)) This should use the existing min or min_t helpers. > int generic_remap_file_range_prep(struct file *file_in, loff_t pos_in, > struct file *file_out, loff_t pos_out, > - loff_t *len, unsigned int remap_flags) > + loff_t *len, unsigned int remap_flags, > + compare_range_t compare_range_fn) Can we keep generic_remap_file_range_prep as-is, and add a new dax_remap_file_range_prep, both sharing a low-level __generic_remap_file_range_prep implementation? And for that implementation I'd also go for classic if/else instead of the function pointer. > +extern int vfs_dedupe_file_range_compare(struct inode *src, loff_t srcoff, > + struct inode *dest, loff_t destoff, > + loff_t len, bool *is_same); no need for the extern.