From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Woodhouse Subject: Re: [RFC] Reinstate NFS exportability for JFFS2. Date: Fri, 01 Aug 2008 02:00:37 +0100 Message-ID: <1217552437.3719.30.camel@shinybook.infradead.org> References: <1209670979.25560.587.camel@pmac.infradead.org> <20080501204820.GA5951@infradead.org> <1209681898.25560.613.camel@pmac.infradead.org> <18458.28833.539314.455215@notabene.brown> <1217541264.1126.15.camel@shinybook.infradead.org> <18578.21997.529551.676627@notabene.brown> <1217551230.3719.15.camel@shinybook.infradead.org> <76bd70e30807311753m2785c6d3kd82edd1fe8b5f8b7@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain Cc: Neil Brown , Christoph Hellwig , linux-fsdevel@vger.kernel.org, linux-nfs@vger.kernel.org, linux-mtd@lists.infradead.org To: chucklever@gmail.com Return-path: Received: from bombadil.infradead.org ([18.85.46.34]:58620 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751425AbYHABAl (ORCPT ); Thu, 31 Jul 2008 21:00:41 -0400 In-Reply-To: <76bd70e30807311753m2785c6d3kd82edd1fe8b5f8b7-JsoAwUIsXosN+BqQ9rBEUg@public.gmane.org> Sender: linux-nfs-owner@vger.kernel.org List-ID: On Thu, 2008-07-31 at 20:53 -0400, Chuck Lever wrote: > For now it is sufficient, IMO. NFSv4 doesn't implement a readdirplus > operation, and the performance benefits of NFSv3 readdirplus are > equivocal -- there isn't a strong desire to replicate the complexity > of NFSv3 readdirplus in NFSv4. I'm not even sure you can do it even > with a single compound RPC, so even in the long run NFSv4 may not ever > have the locking issues that NFSv3 does here. AFAICT NFSv4 does have the same recursion issues already. The call trace goes fs->readdir() ... nfsd4_encode_dirent() ... nfsd4_encode_dirent_fattr() ... lookup_one_len() ... fs->lookup(). Or am I mistaken? > I agree with Neil, though -- as a reviewer, I think the architecture > of your solution is valid, but would need to audit these pretty > closely to get a sense of the individual correctness/appropriateness > of each change. The important part to review is this one, which is fairly close to what XFS has been doing (for local access too) for a long time already: http://git.infradead.org/users/dwmw2/nfsexport-2.6.git?a=commitdiff;h=37f3aae5380eb4ef23a77f3f52b8849a18cee188 -- David Woodhouse Open Source Technology Centre David.Woodhouse@intel.com Intel Corporation