From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Thu, 12 Feb 2009 14:11:52 -0600 From: Nicolas Williams To: "David P. Quigley" Cc: labeled-nfs@linux-nfs.org, nfs-discuss@opensolaris.org, selinux@tycho.nsa.gov, nfsv4@ietf.org Subject: Re: [nfsv4] [Labeled-nfs] New MAC label support Internet Draft posted to IETF website Message-ID: <20090212201152.GB9992@Sun.COM> References: <1232651815.24537.15.camel@moss-terrapins.epoch.ncsc.mil> <4990AD20.3030902@redhat.com> <1234396064.2929.121.camel@moss-terrapins.epoch.ncsc.mil> <20090212153620.GP9992@Sun.COM> <1234468851.2929.157.camel@moss-terrapins.epoch.ncsc.mil> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <1234468851.2929.157.camel@moss-terrapins.epoch.ncsc.mil> Sender: owner-selinux@tycho.nsa.gov List-Id: selinux@tycho.nsa.gov On Thu, Feb 12, 2009 at 03:00:51PM -0500, David P. Quigley wrote: > We also explored a callback for label change notification. I think we > even have the code lying around for the prototype. It worked but Trond > expressed some concern with how well it would scale. The issue Trond > raised is what happens if you relabel an entire file system from under a > set of NFSv4 clients? I'm not sure how much of a concern this will be Surely it would scale no better and no worse than open file delegation... > since 1) File relabeling is supposed to be rare and 2) clients will > probably have a small subset of files open. In the event that you do Reclassification of data is supposed to be rare, though that may vary a lot by environment. The number of files that may be kept open provides a natural limit to how many relabel callbacks will be needed. (A client could OPEN every file at limit cost to itself hoping to overwhelm a server, but that's a separate issue.) > need to relabel the entire file system on the server it might be a good > idea from an administrative perspective to have your clients remount the > NFS shares and flush whatever caches they have. Well, there's no callback to tell clients to flush all writes and remount (or recover). You could simulate a server reboot and force recovery though. Nico -- -- This message was distributed to subscribers of the selinux mailing list. If you no longer wish to subscribe, send mail to majordomo@tycho.nsa.gov with the words "unsubscribe selinux" without quotes as the message.