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 CAF71C32771 for ; Tue, 7 Jan 2020 00:39:51 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id 74CBB206F0 for ; Tue, 7 Jan 2020 00:39:51 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 74CBB206F0 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 BAF548E000A; Mon, 6 Jan 2020 19:39:50 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id B38118E0001; Mon, 6 Jan 2020 19:39:50 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id A00478E000A; Mon, 6 Jan 2020 19:39:50 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0221.hostedemail.com [216.40.44.221]) by kanga.kvack.org (Postfix) with ESMTP id 863DD8E0001 for ; Mon, 6 Jan 2020 19:39:50 -0500 (EST) Received: from smtpin22.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay03.hostedemail.com (Postfix) with SMTP id 2CDBC8249980 for ; Tue, 7 Jan 2020 00:39:50 +0000 (UTC) X-FDA: 76348980540.22.army44_55ce80ce6c940 X-HE-Tag: army44_55ce80ce6c940 X-Filterd-Recvd-Size: 3827 Received: from mail105.syd.optusnet.com.au (mail105.syd.optusnet.com.au [211.29.132.249]) by imf35.hostedemail.com (Postfix) with ESMTP for ; Tue, 7 Jan 2020 00:39:49 +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 B1B7B3A1347; Tue, 7 Jan 2020 11:39:44 +1100 (AEDT) Received: from dave by dread.disaster.area with local (Exim 4.92.3) (envelope-from ) id 1iocuO-0006tT-25; Tue, 07 Jan 2020 11:39:44 +1100 Date: Tue, 7 Jan 2020 11:39:44 +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: <20200107003944.GN23195@dread.disaster.area> References: <20200107001039.GM23195@dread.disaster.area> <20200107001643.GA485121@chrisdown.name> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200107001643.GA485121@chrisdown.name> User-Agent: Mutt/1.10.1 (2018-07-13) X-Optus-CM-Score: 0 X-Optus-CM-Analysis: v=2.3 cv=W5xGqiek 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=CqsqYK7GuNR5ViALEa4A: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 Tue, Jan 07, 2020 at 12:16:43AM +0000, Chris Down wrote: > Dave Chinner writes: > > 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. > > I'm very glad to hear that. I strongly support moving to 64-bit inums in all > cases if there is precedent that it's not a compatibility issue, but from > the comments on my original[0] patch (especially that they strayed from the > original patches' change to use ino_t directly into slab reuse), I'd been > given the impression that it was known to be one. > > From my perspective I have no evidence that inode32 is needed other than the > comment from Jeff above get_next_ino. If that turns out not to be a problem, > I am more than happy to just wholesale migrate 64-bit inodes per-sb in > tmpfs. Well, that's my comment above about 32 bit apps using non-LFS compliant interfaces in this day and age. It's essentially a legacy interface these days, and anyone trying to access a modern linux filesystem (btrfs, XFS, ext4, etc) ion 64 bit systems need to handle 64 bit inodes because they all can create >32bit inode numbers in their default configurations. Cheers, Dave. -- Dave Chinner david@fromorbit.com