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=-1.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,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 285C3C46464 for ; Fri, 10 Aug 2018 15:18:01 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id DE50622422 for ; Fri, 10 Aug 2018 15:18:00 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org DE50622422 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=xmission.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728353AbeHJRsP (ORCPT ); Fri, 10 Aug 2018 13:48:15 -0400 Received: from out02.mta.xmission.com ([166.70.13.232]:45121 "EHLO out02.mta.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727381AbeHJRsP (ORCPT ); Fri, 10 Aug 2018 13:48:15 -0400 Received: from in01.mta.xmission.com ([166.70.13.51]) by out02.mta.xmission.com with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1fo9Ao-0002SF-PF; Fri, 10 Aug 2018 09:17:54 -0600 Received: from [97.119.167.31] (helo=x220.xmission.com) by in01.mta.xmission.com with esmtpsa (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.87) (envelope-from ) id 1fo9Ao-0006vJ-4x; Fri, 10 Aug 2018 09:17:54 -0600 From: ebiederm@xmission.com (Eric W. Biederman) To: Andy Lutomirski Cc: David Howells , viro@zeniv.linux.org.uk, John Johansen , Tejun Heo , selinux@tycho.nsa.gov, Paul Moore , Li Zefan , linux-api@vger.kernel.org, apparmor@lists.ubuntu.com, Casey Schaufler , fenghua.yu@intel.com, Greg Kroah-Hartman , Eric Biggers , linux-security-module@vger.kernel.org, Tetsuo Handa , Johannes Weiner , Stephen Smalley , tomoyo-dev-en@lists.sourceforge.jp, cgroups@vger.kernel.org, torvalds@linux-foundation.org, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, "Theodore Y. Ts'o" , Miklos Szeredi References: <153313703562.13253.5766498657900728120.stgit@warthog.procyon.org.uk> <87d0uqpba5.fsf@xmission.com> <0F2FA70F-8C7E-4D7D-B685-244A76BDB459@amacapital.net> Date: Fri, 10 Aug 2018 10:17:37 -0500 In-Reply-To: <0F2FA70F-8C7E-4D7D-B685-244A76BDB459@amacapital.net> (Andy Lutomirski's message of "Fri, 10 Aug 2018 07:36:17 -0700") Message-ID: <8736vmp7xq.fsf@xmission.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-XM-SPF: eid=1fo9Ao-0006vJ-4x;;;mid=<8736vmp7xq.fsf@xmission.com>;;;hst=in01.mta.xmission.com;;;ip=97.119.167.31;;;frm=ebiederm@xmission.com;;;spf=neutral X-XM-AID: U2FsdGVkX1992sMAMDrG0SeaOpUCajB1dFRXYBOw2nA= X-SA-Exim-Connect-IP: 97.119.167.31 X-SA-Exim-Mail-From: ebiederm@xmission.com Subject: Re: BUG: Mount ignores mount options X-SA-Exim-Version: 4.2.1 (built Thu, 05 May 2016 13:38:54 -0600) X-SA-Exim-Scanned: Yes (on in01.mta.xmission.com) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andy Lutomirski writes: >> On Aug 10, 2018, at 7:05 AM, Eric W. Biederman wrote: >> >> >> There is a serious problem with mount options today that fsopen does not >> address. The problem is that mount options are ignored for block based >> filesystems, and any other type of filesystem that follows the same >> pattern. >> > >> /dev/loop0 /root/loop0-noacl-noquota-nouser_xattr ext4 rw,relatime,nouser_xattr,noacl 0 0 >> /dev/loop0 /root/loop0-acl-quota-user_xattr ext4 rw,relatime,nouser_xattr,noacl 0 0 > > To make sure I understand correctly: the problem is that the second > mount ignored the options because the device was already mounted, > right? Yes. > For the new API, I think the only remotely sane approach is to refuse > to mount or init or whatever you call it an already mounted bdev. If > user code genuinely needs to bind-mount an existing mount that is > known only by its bdev, we can add a specific API just for that. Eric