From: "J. Bruce Fields" Subject: Re: [PATCH 0/4][RFC] NFSv3: implement extended attribute (XATTR) protocol Date: Thu, 8 Oct 2009 13:21:24 -0400 Message-ID: <20091008172123.GA24911@fieldses.org> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: James Morris , Trond Myklebust , linux-nfs@vger.kernel.org, Christoph Hellwig , Casey Schaufler , linux-fsdevel@vger.kernel.org To: Sriram Ramkrishna Return-path: In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-ID: On Thu, Oct 08, 2009 at 09:19:13AM -0700, Sriram Ramkrishna wrote: > On Sat, Sep 19, 2009 at 8:09 AM, James Morris wrote: > > > > > Currently, the code is implemented only to support Linux namespace.name > > xattrs in the "user" namespace. It could be extended to support other > > similar name/value pair xattr implementations (and not far from IRIX wire > > compat), although that's not an aim of this version. There may also be > > some scope for limited support of system xattrs (e.g. 'dumb' security > > label transport), although I've not looked beyond user.* so far. > > > > > James this is great news. I personally am interested (as a consumer) in > setting up better ACL list (ala AFS) than the POSIX model we have now and > trying to implement it using xattr might be the right way. But my > frustration of course was that everybody did xattr in different ways and no > filesystem implementer wanted to go on a limb and implemented such things > without a RFC. Yes, we could allow applications on the client to access essentially arbitrary filesystem-specific functionality. However, this also would allow applications to become dependent on particular features of the exported filesystem. There's some question whether we'd really want to do that. I assume that it was in order to avoid that question that this initial implementation only exports the user.* namespace, since xattr's in that name space are by design not given any special interpretation by the filesystem--they just store and return opaque data. --b. > > > > > > Note that I'll be giving a talk on this at LinuxCon on Thursday: > > http://linuxcon.linuxfoundation.org/meetings/1589 So, in addition to > > discussion here, please come along to the talk if you're at the conf, and > > we may also be able to discuss it at Plumbers in one of the BoFs. > > > > > Ah, I was there, and I was asking around wanting to talk about the issue! > Ah well. > > sri