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=-2.2 required=3.0 tests=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 CF5ECC32771 for ; Tue, 7 Jan 2020 00:10:50 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 9AF552072E for ; Tue, 7 Jan 2020 00:10:50 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 9AF552072E Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=fromorbit.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 311EE8E0008; Mon, 6 Jan 2020 19:10:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 2C2B28E0001; Mon, 6 Jan 2020 19:10:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 1D7048E0008; Mon, 6 Jan 2020 19:10:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0030.hostedemail.com [216.40.44.30]) by kanga.kvack.org (Postfix) with ESMTP id 0857E8E0001 for ; Mon, 6 Jan 2020 19:10:50 -0500 (EST) Received: from smtpin16.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay04.hostedemail.com (Postfix) with SMTP id A677D5003 for ; Tue, 7 Jan 2020 00:10:49 +0000 (UTC) X-FDA: 76348907418.16.bead55_7b94bab478b15 X-HE-Tag: bead55_7b94bab478b15 X-Filterd-Recvd-Size: 3394 Received: from mail105.syd.optusnet.com.au (mail105.syd.optusnet.com.au [211.29.132.249]) by imf10.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Jan 2020 00:10:49 +0000 (UTC) Received: from dread.disaster.area (pa49-180-68-255.pa.nsw.optusnet.com.au [49.180.68.255]) by mail105.syd.optusnet.com.au (Postfix) with ESMTPS id D944A3A2B05; Tue, 7 Jan 2020 11:10:45 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1iocSG-0006iB-01; Tue, 07 Jan 2020 11:10:40 +1100 Date: Tue, 7 Jan 2020 11:10:39 +1100 From: Dave Chinner To: Chris Down Cc: linux-mm@kvack.org, Hugh Dickins , Andrew Morton , Al Viro , Matthew Wilcox , Amir Goldstein , Jeff Layton , Johannes Weiner , Tejun Heo , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH v5 2/2] tmpfs: Support 64-bit inums per-sb Message-ID: <20200107001039.GM23195@dread.disaster.area> References: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=LYdCFQXi c=1 sm=1 tr=0 a=sbdTpStuSq8iNQE8viVliQ==:117 a=sbdTpStuSq8iNQE8viVliQ==:17 a=jpOVt7BSZ2e4Z31A5e1TngXxSK0=:19 a=kj9zAlcOel0A:10 a=Jdjhy38mL1oA:10 a=7-415B0cAAAA:8 a=bVpIlPjQrN2W4rbB-h8A:9 a=CjuIK1q_8ugA:10 a=biEYGPWJfzWAr4FL6Ov7:22 a=pHzHmUro8NiASowvMSCR:22 a=6VlIyEUom7LUIeUMNQJH:22 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 Sun, Jan 05, 2020 at 12:06:05PM +0000, Chris Down wrote: > The default is still set to inode32 for backwards compatibility, but > system administrators can opt in to the new 64-bit inode numbers by > either: > > 1. Passing inode64 on the command line when mounting, or > 2. Configuring the kernel with CONFIG_TMPFS_INODE64=y > > The inode64 and inode32 names are used based on existing precedent from > XFS. Please don't copy this misfeature of XFS. The inode32/inode64 XFS options were a horrible hack made more than 20 years ago when NFSv2 was still in use and 64 bit inodes could not be used for NFSv2 exports. It was then continued to be used because 32bit NFSv3 clients were unable to handle 64 bit inodes. It took 15 years for us to be able to essentially deprecate inode32 (inode64 is the default behaviour), and we were very happy to get that albatross off our necks. In reality, almost everything out there in the world handles 64 bit inodes correctly including 32 bit machines and 32bit binaries on 64 bit machines. And, IMNSHO, there no excuse these days for 32 bit binaries that don't using the *64() syscall variants directly and hence support 64 bit inodes correctlyi out of the box on all platforms. I don't think we should be repeating past mistakes by trying to cater for broken 32 bit applications on 64 bit machines in this day and age. Cheers, Dave. -- Dave Chinner david@fromorbit.com