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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=ham 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 C6B34C433E0 for ; Fri, 5 Feb 2021 20:59:22 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 66A8D64FB4 for ; Fri, 5 Feb 2021 20:59:22 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233290AbhBETQT (ORCPT ); Fri, 5 Feb 2021 14:16:19 -0500 Received: from youngberry.canonical.com ([91.189.89.112]:43983 "EHLO youngberry.canonical.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233537AbhBETOB (ORCPT ); Fri, 5 Feb 2021 14:14:01 -0500 Received: from mail-oi1-f197.google.com ([209.85.167.197]) by youngberry.canonical.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.86_2) (envelope-from ) id 1l888n-00008b-Kr for linux-kernel@vger.kernel.org; Fri, 05 Feb 2021 20:55:45 +0000 Received: by mail-oi1-f197.google.com with SMTP id y62so2815196oiy.15 for ; Fri, 05 Feb 2021 12:55:45 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=QkkmoEPfz/PvJc6Yd3AdkXaGpIKT6BSjX72ihLgbl6M=; b=pabQk1MmjdrHafNBU4F9cbS9c4mmbvWV7FDqqpKVlCREty5yYxDcj/Gb5pPqr+i6ru B7BPnz279gbGdfD9phVx8kxSvBWh+EcKLiwZff5XKmZs/dZ4Tqo0rVsT1AUf5JoEf5Is UMtK4JruI6FJDEWGvQj8ftTYVotG8sKiQRc80nclSNXmwz1CxD5ttNybLrky7uTeHQgP AbpFjnMRTSw9sSfX/8byDOCNmtYnPJXFqIgQLqTuw/o/fmYjOso6b4ACLtA0yC5p90cS nzypfFyNpenrzBKFiXpBTsVNJDqVv7shHx7ywZbGQvP7jyCytCv9qh+XLVnuEJr3LtyL sNhw== X-Gm-Message-State: AOAM533Q87VXLdxGc/KdhQE5aJW9827NAkYS8Yh0IGFzQB5BPkv1huDg UTQMHtkw5W6rC/dLqmfn+lzT08SmWMX3osC0hyk4csdm7Llx5ZnAOmmWalDmSQqncChRn2l5f2X lYbMIQVYRaIyqfWwcxxPXJLHysy41cyVjN5Jg6zohcA== X-Received: by 2002:a9d:5f12:: with SMTP id f18mr4749003oti.282.1612558544678; Fri, 05 Feb 2021 12:55:44 -0800 (PST) X-Google-Smtp-Source: ABdhPJw0tPym7+CLOVDwIItrIhMQpOrUvHBE2Npnq1Ypg8kVSSI4F4SVRY3hpqbOBjAH9Y+o3jUn9A== X-Received: by 2002:a9d:5f12:: with SMTP id f18mr4748993oti.282.1612558544479; Fri, 05 Feb 2021 12:55:44 -0800 (PST) Received: from localhost ([2605:a601:ac0f:820:2b7:eb67:ff8d:8b15]) by smtp.gmail.com with ESMTPSA id r1sm2025770ooq.16.2021.02.05.12.55.43 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Fri, 05 Feb 2021 12:55:43 -0800 (PST) Date: Fri, 5 Feb 2021 14:55:43 -0600 From: Seth Forshee To: Andrew Morton Cc: Hugh Dickins , Chris Down , linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH] tmpfs: Don't use 64-bit inodes by defulat with 32-bit ino_t Message-ID: References: <20210205202159.505612-1-seth.forshee@canonical.com> <20210205124157.c9d855a373362d7bf3d811a7@linux-foundation.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20210205124157.c9d855a373362d7bf3d811a7@linux-foundation.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Feb 05, 2021 at 12:41:57PM -0800, Andrew Morton wrote: > On Fri, 5 Feb 2021 14:21:59 -0600 Seth Forshee wrote: > > > Currently there seems to be an assumption in tmpfs that 64-bit > > architectures also have a 64-bit ino_t. This is not true; s390 at > > least has a 32-bit ino_t. With CONFIG_TMPFS_INODE64=y tmpfs > > mounts will get 64-bit inode numbers and display "inode64" in the > > mount options, but passing the "inode64" mount option will fail. > > This leads to the following behavior: > > > > # mkdir mnt > > # mount -t tmpfs nodev mnt > > # mount -o remount,rw mnt > > mount: /home/ubuntu/mnt: mount point not mounted or bad option. > > > > As mount sees "inode64" in the mount options and thus passes it > > in the options for the remount. > > > > Ideally CONFIG_TMPFS_INODE64 would depend on sizeof(ino_t) < 8, > > but I don't think it's possible to test for this (potentially > > CONFIG_ARCH_HAS_64BIT_INO_T or similar could be added, but I'm > > not sure whether or not that is wanted). So fix this by simply > > refusing to honor the CONFIG_TMPFS_INODE64 setting when > > sizeof(ino_t) < 8. > > How about changing s390 Kconfig so that CONFIG_TMPFS_INODE64 is not enabled? I did do that for our config. I see the s390 defconfig has it enabled, so I will send a patch for that too. But the fact that it can be configured that way and that the code behaves badly still seems problematic. > > > Fixes: ea3271f7196c ("tmpfs: support 64-bit inums per-sb") > > Signed-off-by: Seth Forshee > > With a cc:stable, I assume? Yes, I forgot that. Thanks. Seth