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 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 40EE7C46464 for ; Fri, 10 Aug 2018 15:54:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id E43BE22420 for ; Fri, 10 Aug 2018 15:54:06 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org E43BE22420 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.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 S1728599AbeHJSYa (ORCPT ); Fri, 10 Aug 2018 14:24:30 -0400 Received: from mx3-rdu2.redhat.com ([66.187.233.73]:43278 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1727542AbeHJSY3 (ORCPT ); Fri, 10 Aug 2018 14:24:29 -0400 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 83FBE5A751; Fri, 10 Aug 2018 15:54:03 +0000 (UTC) Received: from warthog.procyon.org.uk (ovpn-120-78.rdu2.redhat.com [10.10.120.78]) by smtp.corp.redhat.com (Postfix) with ESMTP id 38CE62026D65; Fri, 10 Aug 2018 15:53:59 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: <20180810153902.GH21087@thunk.org> References: <20180810153902.GH21087@thunk.org> <87d0uqpba5.fsf@xmission.com> <153313703562.13253.5766498657900728120.stgit@warthog.procyon.org.uk> <22361.1533913891@warthog.procyon.org.uk> To: "Theodore Y. Ts'o" Cc: dhowells@redhat.com, "Eric W. Biederman" , 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, Miklos Szeredi Subject: Re: BUG: Mount ignores mount options MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <28044.1533916438.1@warthog.procyon.org.uk> Date: Fri, 10 Aug 2018 16:53:58 +0100 Message-ID: <28045.1533916438@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.4 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 10 Aug 2018 15:54:03 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Fri, 10 Aug 2018 15:54:03 +0000 (UTC) for IP:'10.11.54.4' DOMAIN:'int-mx04.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'dhowells@redhat.com' RCPT:'' Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Theodore Y. Ts'o wrote: > Even *with* file system support, there's no way today for the VFS to > keep track of whether a pathname resolution came through one > mountpoint or another, so I can't do something like this: Ummm... Isn't that encoded in the vfsmount pointer in struct path? However, the case folding stuff - is that a superblockism of a mountpointism? > So if the file system has been mounted with one set of mount options, > and you want to try to mount it with a conflicting set of mount > options and you don't want it to silently ignore the mount options, > the *only* thing we can today is to refuse the mount and return an > error. With fsopen() there is the option to have the filesystem and the LSM attempt to compare the non-key[*] mount options and reject the attempt to share if they differ in any way. David [*] sget lookup keys, that is.