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=-3.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT 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 E9DBEC282DD for ; Wed, 8 Jan 2020 14:38:05 +0000 (UTC) Received: from kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by mail.kernel.org (Postfix) with ESMTP id A610020705 for ; Wed, 8 Jan 2020 14:38:05 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="uTkbRiLM" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org A610020705 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=gmail.com Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=owner-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix) id 3EF7F8E0008; Wed, 8 Jan 2020 09:38:05 -0500 (EST) Received: by kanga.kvack.org (Postfix, from userid 40) id 39F4C8E0001; Wed, 8 Jan 2020 09:38:05 -0500 (EST) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id 268308E0008; Wed, 8 Jan 2020 09:38:05 -0500 (EST) X-Delivered-To: linux-mm@kvack.org Received: from forelay.hostedemail.com (smtprelay0130.hostedemail.com [216.40.44.130]) by kanga.kvack.org (Postfix) with ESMTP id 0DF168E0001 for ; Wed, 8 Jan 2020 09:38:05 -0500 (EST) Received: from smtpin03.hostedemail.com (10.5.19.251.rfc1918.com [10.5.19.251]) by forelay01.hostedemail.com (Postfix) with SMTP id B0D1E180AD807 for ; Wed, 8 Jan 2020 14:38:04 +0000 (UTC) X-FDA: 76354721688.03.seed00_295b041b98363 X-HE-Tag: seed00_295b041b98363 X-Filterd-Recvd-Size: 5073 Received: from mail-lj1-f196.google.com (mail-lj1-f196.google.com [209.85.208.196]) by imf29.hostedemail.com (Postfix) with ESMTP for ; Wed, 8 Jan 2020 14:38:04 +0000 (UTC) Received: by mail-lj1-f196.google.com with SMTP id m26so3511234ljc.13 for ; Wed, 08 Jan 2020 06:38:03 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=DJue8/6LAi2tlw85/kLQgrOu38pX1buqz3xnndYdkb4=; b=uTkbRiLMq4uyDlANwRVvyDvo6KFM4b7xpmkLPFOfEsST7+xd21eWq0XU/PjiYqwyXR qCU7bfDg7Ub3DLKcputeiysZldmRMLeslqYpoGcQ6dz+9W+1xleh62Hkn0khWkWcCD1T PE7lrjGfFpBS8l9EP+uY7wD9jQovSQn7gcUvtkADOxpCbFZ6IjElU/9Uq5IQiDR47dd7 I4txYIFzz0iQIw7YYg6auAlRSWJ6O9hNkWP3uokOUsBABb8lmcT6HjbPEzqtSljIiN8y aRhgNNk49/2FLU/LAvbKIQ66deji5cDn4jyh6CQxd6aK3wujxu5mfX3+McsqQjcuEEs7 uojw== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=DJue8/6LAi2tlw85/kLQgrOu38pX1buqz3xnndYdkb4=; b=T2WwLQFKQqczXeTjSiMyfc6ZSKFvA+pXoSwOIcHDjGJjVVFbjkqCkiB3khnUGopJ06 znk5Ji9SgET5iVGHHiRqIUYY6XGXnN/504Ld5fyU4jiG2tDIeTXjPgDHvjJT3OQYE7+E C6odmkM4UNgI7fJcdJ0aF0BOTzBixwOzCDC6pqsvyMOFKw/xHwgq7MFLMRJPZVmsA1Da ZnptWcqNDBmaUD1ZajPUBRwQdgh0+f9OMPm6TlW2u7bBO35WvioyGJHLaElwD4t/aVii ngn85aTDlLUVztoQSIrPIJgVCUg9gnQZSzuCbf8HkikIz1Kjn8250SABryc3K7uvoRNn Ot5g== X-Gm-Message-State: APjAAAUbSyBMXpG/dXgwPgGGiWRFhB9vSm+AWZjJVQGrXtJQoG0ZPR7K gSwQxXuCyxBplYLFEXbl5mQ= X-Google-Smtp-Source: APXvYqxfw2SjsgOrvnNQobjIGJ3Q2def72Hm4QfXCeKCU74uYYOI4EPLHVPaAmihbFLUuhmyxmwbow== X-Received: by 2002:a2e:98ca:: with SMTP id s10mr3198466ljj.160.1578494282566; Wed, 08 Jan 2020 06:38:02 -0800 (PST) Received: from localhost.localdomain (h-88-110.A230.priv.bahnhof.se. [212.85.88.110]) by smtp.gmail.com with ESMTPSA id r2sm1493279lfn.13.2020.01.08.06.37.58 (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Wed, 08 Jan 2020 06:37:59 -0800 (PST) From: Mikael Magnusson To: david@fromorbit.com Cc: akpm@linux-foundation.org, amir73il@gmail.com, chris@chrisdown.name, hannes@cmpxchg.org, hughd@google.com, jlayton@kernel.org, kernel-team@fb.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, tj@kernel.org, viro@zeniv.linux.org Subject: Re: [PATCH v5 2/2] tmpfs: Support 64-bit inums per-sb Date: Wed, 8 Jan 2020 15:37:52 +0100 Message-Id: <20200108143752.9475-1-mikachu@gmail.com> X-Mailer: git-send-email 2.15.1 In-Reply-To: <20200107001039.GM23195@dread.disaster.area> References: <20200107001039.GM23195@dread.disaster.area> 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: Dave Chinner writes: > 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. Hi, It's unfortunately not true that everything handles this correctly. 32-bit binaries for games on Steam that use stat() without the 64 is so prevalent that I got tired of adding the LD_PRELOAD wrapper script and just patched out the EOVERFLOW return from glibc instead. (They obviously don't care about the inode value at all, and I don't use any other 32-bit binaries that do). This is probably a class of binaries you don't care very much about, and not very likely to be installed on a tmpfs that has wrapped around, but I thought it was worth mentioning that they do exist anyway. -- Mikael Magnusson