From: Jeff Layton Subject: Re: [RFC] new client gssd upcall Date: Thu, 19 Jun 2008 15:11:17 -0400 Message-ID: <20080619151117.20ddc00e@tleilax.poochiereds.net> References: <1213397442-15611-1-git-send-email-bfields@citi.umich.edu> <20080616102859.66fa6a34@tleilax.poochiereds.net> <20080617213622.GA5849@fieldses.org> <1213739969.7288.90.camel@localhost> <485A7D2D.4060206@citi.umich.edu> <20080619114929.5c211ec9@tleilax.poochiereds.net> <1213895182.7120.13.camel@localhost> <20080619132720.6bce2bb9@tleilax.poochiereds.net> <1213899199.7120.22.camel@localhost> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Cc: Olga Kornievskaia , "J. Bruce Fields" , kwc@citi.umich.edu, linux-nfs@vger.kernel.org To: Trond Myklebust Return-path: Received: from mx1.redhat.com ([66.187.233.31]:42827 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751671AbYFSTLh (ORCPT ); Thu, 19 Jun 2008 15:11:37 -0400 In-Reply-To: <1213899199.7120.22.camel@localhost> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 19 Jun 2008 14:13:19 -0400 Trond Myklebust wrote: > On Thu, 2008-06-19 at 13:27 -0400, Jeff Layton wrote: > > There's also no reason we couldn't use keys for > > idmap upcalls as well. I'm considering them for a similar idmap scheme > > for CIFS. > > Ewww.... NACK, NACK, NACK, NACK.... > > There is a perfectly good reason why you wouldn't ever want to use keys > for idmap upcalls: keys are user/process/thread objects while idmapd > entries are NFSv4-namespace objects. > My thinking for CIFS is to use keys to do the upcall and copy the mapping into a cache that we'll manage independently of the key cache. The CIFS case is a little different though. We're not mapping usernames to uid's and vice-versa, but Windows RID's to unix uid's. Still, it's a somewhat similar problem. The amount of data that we're dealing with in an idmap upcall is pretty small, so copying it and then destroying the key wouldn't involve a lot of overhead. That may not be palatable for NFS though. -- Jeff Layton