From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Latchesar Ionkov" Subject: Re: openg and path_to_handle Date: Wed, 6 Dec 2006 18:19:41 -0500 Message-ID: References: <6.2.3.4.2.20061127213243.04f786c0@cic-mail.lanl.gov> <20061129090450.GA16296@infradead.org> <20061129122313.GG14315@parisc-linux.org> <20061129123913.GA15994@infradead.org> <4570ACD1.7060800@mcs.anl.gov> <4574BF52.6090600@mcs.anl.gov> <20061206094805.GB33919298@melbourne.sgi.com> <4576E783.7020402@mcs.anl.gov> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Cc: "David Chinner" , "Christoph Hellwig" , "Matthew Wilcox" , "Gary Grider" , linux-fsdevel@vger.kernel.org Return-path: Received: from nf-out-0910.google.com ([64.233.182.191]:52674 "EHLO nf-out-0910.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S937780AbWLFXTo (ORCPT ); Wed, 6 Dec 2006 18:19:44 -0500 Received: by nf-out-0910.google.com with SMTP id o25so701243nfa for ; Wed, 06 Dec 2006 15:19:43 -0800 (PST) To: "Rob Ross" In-Reply-To: <4576E783.7020402@mcs.anl.gov> Content-Disposition: inline Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On 12/6/06, Rob Ross wrote: > David Chinner wrote: > > On Tue, Dec 05, 2006 at 05:47:16PM +0100, Latchesar Ionkov wrote: > >> On 12/5/06, Rob Ross wrote: > >>> Hi, > >>> > >>> I agree that it is not feasible to add new system calls every time > >>> somebody has a problem, and we don't take adding system calls lightly. > >>> However, in this case we're talking about an entire *community* of > >>> people (high-end computing), not just one or two people. Of course it > >>> may still be the case that that community is not important enough to > >>> justify the addition of system calls; that's obviously not my call to make! > >> I have the feeling that openg stuff is rushed without looking into all > >> solutions, that don't require changes to the current interface. > > > > I also get the feeling that interfaces that already do this > > open-by-handle stuff haven't been explored either. > > > > Does anyone here know about the XFS libhandle API? This has been > > around for years and it does _exactly_ what these proposed syscalls > > are supposed to do (and more). > > > > See: > > > > http://techpubs.sgi.com/library/tpl/cgi-bin/getdoc.cgi?coll=linux&db=man&fname=/usr/share/catman/man3/open_by_handle.3.html&srch=open_by_handle > > > > For the libhandle man page. Basically: > > > > openg == path_to_handle > > sutoc == open_by_handle > > > > And here for the userspace code: > > > > http://oss.sgi.com/cgi-bin/cvsweb.cgi/xfs-cmds/xfsprogs/libhandle/ > > > > Cheers, > > > > Dave. > > Thanks for pointing these out Dave. These are indeed along the same > lines as the openg()/openfh() approach. The open-by-handle makes a little more sense, because the "handle" is not opened, it only points to a resolved file. As I mentioned before, it doesn't make much sense to bundle in openg name resolution and file open. Still I am not convinced that we need two ways of "finding" files. Thanks, Lucho