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 Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 1155DC433FE for ; Wed, 30 Mar 2022 10:58:33 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 7D04C8D0003; Wed, 30 Mar 2022 06:58:32 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 77D5A8D0001; Wed, 30 Mar 2022 06:58:32 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 61DBF8D0003; Wed, 30 Mar 2022 06:58:32 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0081.hostedemail.com [216.40.44.81]) by kanga.kvack.org (Postfix) with ESMTP id 53D4D8D0001 for ; Wed, 30 Mar 2022 06:58:32 -0400 (EDT) Received: from smtpin17.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay02.hostedemail.com (Postfix) with ESMTP id E75C5A45A0 for ; Wed, 30 Mar 2022 10:58:31 +0000 (UTC) X-FDA: 79300754022.17.183BCCD Received: from heian.cn.fujitsu.com (mail.cn.fujitsu.com [183.91.158.132]) by imf26.hostedemail.com (Postfix) with ESMTP id ABFAF14000E for ; Wed, 30 Mar 2022 10:58:30 +0000 (UTC) IronPort-Data: =?us-ascii?q?A9a23=3AgNM4v69uJjWCds008lY+DrUD63+TJUtcMsCJ2f8?= =?us-ascii?q?bfWQNrUog1TAPymEXX2+EOv6PYjP9KNokaYqy8UwPvZHdzYIwTVdlrnsFo1Bi8?= =?us-ascii?q?5ScXYvDRqvT04J+FuWaFQQ/qZx2huDodKjYdVeB4Ef9WlTdhSMkj/vQHOKlULe?= =?us-ascii?q?s1h1ZHmeIdg9w0HqPpMZp2uaEsfDha++8kYuaT//3YTdJ6BYoWo4g0J9vnTs01?= =?us-ascii?q?BjEVJz0iXRlDRxDlAe2e3D4l/vzL4npR5fzatE88uJX24/+IL+FEmPxp3/BC/u?= =?us-ascii?q?ulPD1b08LXqXPewOJjxK6WYD72l4b+HN0if19aZLwam8O49mNt8pswdNWpNq+T?= =?us-ascii?q?xw1FqPRmuUBSAQeGCZ7VUFD0OadeiDu6JzNnyUqdFOpmZ2CFnoeMYQG++pfD3t?= =?us-ascii?q?J8PsCIjERKBuEgoqewLm7YuhqiN4qIMTiMMUYoH4I5T3QC7AkB4/CR6HL7NpD9?= =?us-ascii?q?DY2ms1KW/3ZYqIxZThwaxLPSx5CIFEaDNQ5hujArn3+dSBI7VeQjakp6mPQigt?= =?us-ascii?q?r39DFNsTZe9mPbcFUhVqD4GbH+XnpRB0XKrS3yzOD/zSnhvLnmjnyU4YfUra/8?= =?us-ascii?q?5ZChFyV23xWBgYaWEW2pdGnhUOkHdFSMUoZ/mwpt6da3EiqSMTtGh61uniJujY?= =?us-ascii?q?CVNdKVe438geAzuzT+QnxLmwFSCNRLcwor+coSjEwkFyEhdXkAXpoqrL9dJ433?= =?us-ascii?q?t94thvrYW5MczBEPnRCEGM4DxDYiNlbpnryohxLScZZVuHIJAw=3D?= IronPort-HdrOrdr: =?us-ascii?q?A9a23=3A7pXWoarUc0yRRXUzYrKOZWAaV5oUeYIsimQD?= =?us-ascii?q?101hICG9vPbo7vxG/c5rrSMc7Qx6ZJhOo6HkBEDtewK/yXcx2/hzAV7AZmjbUQ?= =?us-ascii?q?mTXeVfBOLZqlWKJ8S9zI5gPMxbAs9D4bPLfD5HZAXBjDVQ0exM/DBKys+VbC7l?= =?us-ascii?q?oUtQcQ=3D=3D?= X-IronPort-AV: E=Sophos;i="5.88,333,1635177600"; d="scan'208";a="123091868" Received: from unknown (HELO cn.fujitsu.com) ([10.167.33.5]) by heian.cn.fujitsu.com with ESMTP; 30 Mar 2022 18:58:28 +0800 Received: from G08CNEXMBPEKD05.g08.fujitsu.local (unknown [10.167.33.204]) by cn.fujitsu.com (Postfix) with ESMTP id E2D7E4D17160; Wed, 30 Mar 2022 18:58:22 +0800 (CST) Received: from G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.85) by G08CNEXMBPEKD05.g08.fujitsu.local (10.167.33.204) with Microsoft SMTP Server (TLS) id 15.0.1497.23; Wed, 30 Mar 2022 18:58:22 +0800 Received: from [10.167.201.8] (10.167.201.8) by G08CNEXCHPEKD09.g08.fujitsu.local (10.167.33.209) with Microsoft SMTP Server id 15.0.1497.23 via Frontend Transport; Wed, 30 Mar 2022 18:58:22 +0800 Message-ID: <4ed8baf7-7eb9-71e5-58ea-7c73b7e5bb73@fujitsu.com> Date: Wed, 30 Mar 2022 18:58:21 +0800 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (Windows NT 10.0; Win64; x64; rv:91.0) Gecko/20100101 Thunderbird/91.7.0 Subject: Re: [PATCH v11 1/8] dax: Introduce holder for dax_device To: Christoph Hellwig CC: Dan Williams , Linux Kernel Mailing List , linux-xfs , Linux NVDIMM , Linux MM , linux-fsdevel , "Darrick J. Wong" , david , Jane Chu References: <20220227120747.711169-1-ruansy.fnst@fujitsu.com> <20220227120747.711169-2-ruansy.fnst@fujitsu.com> <4fd95f0b-106f-6933-7bc6-9f0890012b53@fujitsu.com> <15a635d6-2069-2af5-15f8-1c0513487a2f@fujitsu.com> From: Shiyang Ruan In-Reply-To: Content-Type: text/plain; charset="UTF-8"; format=flowed X-yoursite-MailScanner-ID: E2D7E4D17160.A1BE2 X-yoursite-MailScanner: Found to be clean X-yoursite-MailScanner-From: ruansy.fnst@fujitsu.com X-Rspam-User: X-Stat-Signature: axscwaxp7fedxwy6nprjcuto4d1rtdjy Authentication-Results: imf26.hostedemail.com; dkim=none; spf=none (imf26.hostedemail.com: domain of ruansy.fnst@fujitsu.com has no SPF policy when checking 183.91.158.132) smtp.mailfrom=ruansy.fnst@fujitsu.com; dmarc=fail reason="No valid SPF, No valid DKIM" header.from=fujitsu.com (policy=none) X-Rspamd-Server: rspam01 X-Rspamd-Queue-Id: ABFAF14000E X-HE-Tag: 1648637910-975661 Content-Transfer-Encoding: quoted-printable X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: =E5=9C=A8 2022/3/30 18:13, Christoph Hellwig =E5=86=99=E9=81=93: > On Wed, Mar 30, 2022 at 06:03:01PM +0800, Shiyang Ruan wrote: >> >> Because I am not sure if the offset between each layer is page aligned= . For >> example, when pmem dirver handles ->memory_failure(), it should subtra= ct its >> ->data_offset when it calls dax_holder_notify_failure(). >=20 > If they aren't, none of the DAX machinery would work. OK. Got it. So, use page-based function signature for ->memory_failure(): int (*memory_failure)(struct dev_pagemap *pgmap, unsigned long pfn, unsigned long nr_pfns, int flags); As the code I pasted before, pmem driver will subtract its=20 ->data_offset, which is byte-based. And the filesystem who implements=20 ->notify_failure() will calculate the offset in unit of byte again. So, leave its function signature byte-based, to avoid repeated conversion= s. int (*notify_failure)(struct dax_device *dax_dev, u64 offset, u64 len, int mf_flags); What do you think? -- Thanks, Ruan.