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 32014C433EF for ; Wed, 30 Mar 2022 16:18:18 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id 635106B0072; Wed, 30 Mar 2022 12:18:17 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id 5E5476B0073; Wed, 30 Mar 2022 12:18:17 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 4ABCA8D0001; Wed, 30 Mar 2022 12:18:17 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (relay.a.hostedemail.com [64.99.140.24]) by kanga.kvack.org (Postfix) with ESMTP id 37E746B0072 for ; Wed, 30 Mar 2022 12:18:17 -0400 (EDT) Received: from smtpin07.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id EEBB2206F1 for ; Wed, 30 Mar 2022 16:18:16 +0000 (UTC) X-FDA: 79301559834.07.440DA70 Received: from ams.source.kernel.org (ams.source.kernel.org [145.40.68.75]) by imf10.hostedemail.com (Postfix) with ESMTP id 68AE4C000C for ; Wed, 30 Mar 2022 16:18:16 +0000 (UTC) Received: from smtp.kernel.org (relay.kernel.org [52.25.139.140]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by ams.source.kernel.org (Postfix) with ESMTPS id 92638B81BB7; Wed, 30 Mar 2022 16:18:14 +0000 (UTC) Received: by smtp.kernel.org (Postfix) with ESMTPSA id 51A51C340EC; Wed, 30 Mar 2022 16:18:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1648657093; bh=cjFQuqoRMfu2TXAsiXRv9EQjKvH+MdFIXY9uc5fhIeE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=qL9r9Yws/hUGzKuvIFY+RbuwntrMSK4P43CyL2/dnXSTyynijAjGxTx5jk0MciJBS ZU3K1UIDqMzxA88epboJ1p59x5irJJj2JLdT3IY0tPJYmpTuab09WoUfTrxDR16Dfq r8N4tXQdQIaPnia1AslHnGmOplVqsKsaI34w3RLi6u1e7bfXjxM+6aYBDQb0MMyTSr YPN+3zKng+bKVx0qXsPftkro+4iih8aIVgkJzS6owkJGyF1RHMzDG9okK9EYv0u6/k DPUA6Xn7fDXsQPvseUvtae8Ads0cYctEDf9QDUz5BscGpr2wMHyw7xssUbm6ZRtK/f ndefofeH+jTig== Date: Wed, 30 Mar 2022 09:18:12 -0700 From: "Darrick J. Wong" To: Christoph Hellwig Cc: Shiyang Ruan , Dan Williams , Linux Kernel Mailing List , linux-xfs , Linux NVDIMM , Linux MM , linux-fsdevel , david , Jane Chu Subject: Re: [PATCH v11 1/8] dax: Introduce holder for dax_device Message-ID: <20220330161812.GA27649@magnolia> 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> <4ed8baf7-7eb9-71e5-58ea-7c73b7e5bb73@fujitsu.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Authentication-Results: imf10.hostedemail.com; dkim=pass header.d=kernel.org header.s=k20201202 header.b=qL9r9Yws; spf=pass (imf10.hostedemail.com: domain of djwong@kernel.org designates 145.40.68.75 as permitted sender) smtp.mailfrom=djwong@kernel.org; dmarc=pass (policy=none) header.from=kernel.org X-Rspam-User: X-Rspamd-Server: rspam10 X-Rspamd-Queue-Id: 68AE4C000C X-Stat-Signature: cy57ak7ozsb7n9scgxicxjz8q4xnk81p X-HE-Tag: 1648657096-742071 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: On Wed, Mar 30, 2022 at 08:49:29AM -0700, Christoph Hellwig wrote: > On Wed, Mar 30, 2022 at 06:58:21PM +0800, Shiyang Ruan wrote: > > As the code I pasted before, pmem driver will subtract its ->data_offset, > > which is byte-based. And the filesystem who implements ->notify_failure() > > will calculate the offset in unit of byte again. > > > > So, leave its function signature byte-based, to avoid repeated conversions. > > I'm actually fine either way, so I'll wait for Dan to comment. FWIW I'd convinced myself that the reason for using byte units is to make it possible to reduce the pmem failure blast radius to subpage units... but then I've also been distracted for months. :/ --D