From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from relay.sgi.com (relay1.corp.sgi.com [137.38.102.111]) by oss.sgi.com (Postfix) with ESMTP id 4C9817F3F for ; Thu, 27 Jun 2013 08:02:19 -0500 (CDT) Received: from cuda.sgi.com (cuda3.sgi.com [192.48.176.15]) by relay1.corp.sgi.com (Postfix) with ESMTP id 275BA8F804B for ; Thu, 27 Jun 2013 06:02:15 -0700 (PDT) Received: from youngberry.canonical.com (youngberry.canonical.com [91.189.89.112]) by cuda.sgi.com with ESMTP id iK7WMFh8w3SwTPQl for ; Thu, 27 Jun 2013 06:02:14 -0700 (PDT) Date: Thu, 27 Jun 2013 08:02:05 -0500 From: Serge Hallyn Subject: Re: [PATCH v2 RFC] userns: Convert xfs to use kuid/kgid where appropriate Message-ID: <20130627130205.GA4003@sergelap> References: <20130619110948.0bfafa2b@oracle.com> <20130620001341.GM29338@dastard> <20130620095410.1917d235@oracle.com> <20130620220311.GT29376@dastard> <20130621111420.5592707e@oracle.com> <20130624003316.GH29376@dastard> <20130624091035.6274800f@oracle.com> <20130626020924.GD29376@dastard> <20130626173017.5100327a@oracle.com> <20130626224410.GB28426@dastard> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20130626224410.GB28426@dastard> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Errors-To: xfs-bounces@oss.sgi.com Sender: xfs-bounces@oss.sgi.com To: Dave Chinner Cc: "Eric W. Biederman" , Brian Foster , Dwight Engen , xfs@oss.sgi.com Quoting Dave Chinner (david@fromorbit.com): > On Wed, Jun 26, 2013 at 05:30:17PM -0400, Dwight Engen wrote: > > On Wed, 26 Jun 2013 12:09:24 +1000 > > Dave Chinner wrote: > > > > We do need to decide on the di_uid that comes back from bulkstat. > > > > Right now it is returning on disk (== init_user_ns) uids. It looks > > > > to me like xfsrestore is using the normal vfs routines (chown, I might not be helpful here, (as despite having used xfs for years I've not used these features) but feel like I should try based on what I see in the manpages. Here is my understanding: Assume you're a task in a child userns, where you have host uids 100000-110000 mapped to container uids 0-10000, 1. bulkstat is an xfs_ioctl command, right? It should return the mapped uids (0-10000). 2. xfsdump should store the uids as seen in the caller's namespace. If xfsdump is done from the container, the dump should show uids 0-10000. 3. xfsrestore should use be run from the desired namespace. If you did xfsdump from the host ns, you should then xfsrestore from the host ns. Then inside the container those uids (100000-110000) will be mapped to your uids (0-10000). 4. If you xfsdump in this container, then xfsrestore in another container where you have 200000-210000 mapped to 0-10000, the dump image will have uids 0-10000. The restored image will have container uids 0-10000, while on the underlying host media it will be uids 200000-210000. 5. If you xfsdump in this container then xfsrestore on the host, then the host uids 0-10000 will be used on the underlying media. The container would be unable to read this files as the uids do not map into the container. -serge _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs