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=-2.4 required=3.0 tests=DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT 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 2B562C46464 for ; Sat, 11 Aug 2018 01:47:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C979E22433 for ; Sat, 11 Aug 2018 01:47:07 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=thunk.org header.i=@thunk.org header.b="kgwkahbJ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org C979E22433 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=mit.edu 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 S1727123AbeHKETO (ORCPT ); Sat, 11 Aug 2018 00:19:14 -0400 Received: from imap.thunk.org ([74.207.234.97]:33184 "EHLO imap.thunk.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725199AbeHKETO (ORCPT ); Sat, 11 Aug 2018 00:19:14 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=thunk.org; s=ef5046eb; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=nWXc6vZEs9KhppBzlPhwuChgkTa4gq2ZEZL2+ARQpM4=; b=kgwkahbJIVD+QOLq9z7YZK4cRe +vPC4T+vOOcvHXj+P7uDVrRqGZAbZudYedjHfE9UxQpgSNVMvKumIm+7DLjUi8Bwk29b3iHS9uWbF BqH6gni5r81SNepZVL+MUYVJF7qxicAR+V14jTJ+EZVHgAavsoo5C9fjAWCSihBVbEMk=; Received: from root (helo=callcc.thunk.org) by imap.thunk.org with local-esmtp (Exim 4.89) (envelope-from ) id 1foIyz-00066a-2M; Sat, 11 Aug 2018 01:46:21 +0000 Received: by callcc.thunk.org (Postfix, from userid 15806) id 5F6D37A5B5D; Fri, 10 Aug 2018 21:46:19 -0400 (EDT) Date: Fri, 10 Aug 2018 21:46:19 -0400 From: "Theodore Y. Ts'o" To: "Eric W. Biederman" Cc: Al Viro , David Howells , 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 Message-ID: <20180811014619.GA14368@thunk.org> Mail-Followup-To: "Theodore Y. Ts'o" , "Eric W. Biederman" , Al Viro , David Howells , 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 References: <153313703562.13253.5766498657900728120.stgit@warthog.procyon.org.uk> <87d0uqpba5.fsf@xmission.com> <20180810151606.GA6515@ZenIV.linux.org.uk> <87pnypiufr.fsf@xmission.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <87pnypiufr.fsf@xmission.com> User-Agent: Mutt/1.10.1 (2018-07-13) X-SA-Exim-Connect-IP: X-SA-Exim-Mail-From: tytso@thunk.org X-SA-Exim-Scanned: No (on imap.thunk.org); SAEximRunCond expanded to false Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Aug 10, 2018 at 08:05:44PM -0500, Eric W. Biederman wrote: > > My complaint is that the current implemented behavior of practically > every filesystem in the kernel, is that it will ignore mount options > when mounted a second time. The file system is ***not*** mounted a second time. The design bug is that we allow bind mounts to be specified via a block device. A bind mount is not "a second mount" of the file system. Bind mounts != mounts. I had assumed we had allowed bind mounts to be specified via the block device because of container use cases. If the container folks don't want it, I would be pushing to simply not allow bind mounts to be specified via block device at all. The only reason why we should support it is because we don't want to break scripts; and if the goal is not to break scripts, then we have to keep to the current semantics, however broken you think it is. - Ted