From: Alan Cox Subject: Re: [PATCH 1/3] implement uid and gid mount options for ext2 Date: Thu, 2 Aug 2012 13:06:42 +0100 Message-ID: <20120802130642.46b12c59@pyramind.ukuu.org.uk> References: <1343908443-17369-1-git-send-email-ludwig.nussel@suse.de> <1343908443-17369-2-git-send-email-ludwig.nussel@suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, Jan Kara (maintainer:EXT2 FILE SYSTEM), Rob Landley (maintainer:DOCUMENTATION), Andrew Morton (maintainer:EXT3 FILE SYSTEM), Andreas Dilger (maintainer:EXT3 FILE SYSTEM), "Theodore Ts'o" (maintainer:EXT4 FILE SYSTEM), linux-ext4@vger.kernel.org (open list:EXT2 FILE SYSTEM), linux-doc@vger.kernel.org (open list:DOCUMENTATION) To: Ludwig Nussel Return-path: Received: from lxorguk.ukuu.org.uk ([81.2.110.251]:57634 "EHLO lxorguk.ukuu.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750949Ab2HBMC1 (ORCPT ); Thu, 2 Aug 2012 08:02:27 -0400 In-Reply-To: <1343908443-17369-2-git-send-email-ludwig.nussel@suse.de> Sender: linux-ext4-owner@vger.kernel.org List-ID: > +uid=n[:m] Make all files appear to belong to uid n. > + Useful for e.g. removable media with fstab > + options 'user,uid=useruid'. The optional second > + uid m is actually written to the file system. So what happens if I insert a USB key containing a device node to the hard disk ? Why is this functionality useful in the current form ? (ie I think you need an actual rational security model first) Also why is this at the per fs level duplicating stuff each time rather than at the vfs level - this seems to be vfs level functionality. > + > +gid=n[:m] Make all files appear to belong to gid n. > + The optional second gid m is actually written to > + the file system. Your documentation seems only half completed ? Alan