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=-3.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS 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 CC3C4C433E0 for ; Tue, 9 Mar 2021 16:19:37 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 971E565237 for ; Tue, 9 Mar 2021 16:19:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231246AbhCIQTD (ORCPT ); Tue, 9 Mar 2021 11:19:03 -0500 Received: from mx2.suse.de ([195.135.220.15]:47662 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229815AbhCIQSt (ORCPT ); Tue, 9 Mar 2021 11:18:49 -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 D8065AF0C; Tue, 9 Mar 2021 16:18:47 +0000 (UTC) Date: Tue, 9 Mar 2021 10:19:06 -0600 From: Goldwyn Rodrigues 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 Subject: Re: [PATCH v2 00/10] fsdax,xfs: Add reflink&dedupe support for fsdax Message-ID: <20210309161906.jjd7iw2y6hcst5c3@fiona> References: <20210226002030.653855-1-ruansy.fnst@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210226002030.653855-1-ruansy.fnst@fujitsu.com> Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Hi Shiang, Thanks for picking up this work. On 8:20 26/02, 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. How does this work for read sequence for two different files mapped to the same extent, both residing in DAX? If two different files read the same shared extent, which file would resultant page->mapping->host point to? This problem is listed as a TODO over dax_associate_entry() and is still not fixed. -- Goldwyn