From mboxrd@z Thu Jan  1 00:00:00 1970
From: "Theodore Y. Ts'o" <tytso@mit.edu>
Subject: Re: [PATCH 24/32] vfs: syscall: Add fsopen() to prepare for
 superblock creation [ver #9]
Date: Thu, 12 Jul 2018 22:35:55 -0400
Message-ID: <20180713023555.GE28610@thunk.org>
References: <153126248868.14533.9751473662727327569.stgit@warthog.procyon.org.uk>
 <153126264966.14533.3388004240803696769.stgit@warthog.procyon.org.uk>
 <686E805C-81F3-43D0-A096-50C644C57EE3@amacapital.net>
 <22370.1531293761@warthog.procyon.org.uk>
 <CALCETrU3kbh-ZRHDj7-Asq+OH-35dQ2p_erpHpYUvN5+BdAoVQ@mail.gmail.com>
 <7002.1531407244@warthog.procyon.org.uk>
 <CA+55aFx+xm333ZZ7d2Z39QuhDu=0XM6nTMChbHvWQOXNk32yxw@mail.gmail.com>
 <16699.1531426991@warthog.procyon.org.uk>
 <18233.1531430797@warthog.procyon.org.uk>
 <22105.1531436081@warthog.procyon.org.uk>
Mime-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Return-path: <linux-kernel-owner@vger.kernel.org>
Content-Disposition: inline
In-Reply-To: <22105.1531436081@warthog.procyon.org.uk>
Sender: linux-kernel-owner@vger.kernel.org
To: David Howells <dhowells@redhat.com>
Cc: Linus Torvalds <torvalds@linux-foundation.org>, Andrew Lutomirski <luto@kernel.org>, Al Viro <viro@zeniv.linux.org.uk>, Linux API <linux-api@vger.kernel.org>, linux-fsdevel <linux-fsdevel@vger.kernel.org>, Linux Kernel Mailing List <linux-kernel@vger.kernel.org>, Jann Horn <jannh@google.com>
List-Id: linux-api@vger.kernel.org

On Thu, Jul 12, 2018 at 11:54:41PM +0100, David Howells wrote:
> 
> Would that mean then that doing:
> 
> 	mount /dev/sda3 /a
> 	mount /dev/sda3 /b
> 
> would then fail on the second command because /dev/sda3 is already open
> exclusively?

Good point.  One workaround would be to require an open with O_PATH instead.

     	     	 	    	     	- Ted