From mboxrd@z Thu Jan 1 00:00:00 1970 From: "J. Bruce Fields" Subject: Re: [PATCH 6/6] nfs: disable leases over NFS Date: Wed, 4 Jul 2007 19:22:21 -0400 Message-ID: <20070704232221.GF26764@fieldses.org> References: <6e0beaf3e950494a6903571f0b5c9b61fc7bf650.1183143819.git.bfields@citi.umich.edu> <20070630092516.GD22050@infradead.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Andrew Morton , linux-fsdevel@vger.kernel.org, Peter Staubach , Trond Myklebust To: Christoph Hellwig Return-path: Received: from mail.fieldses.org ([66.93.2.214]:40535 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753143AbXGDXW1 (ORCPT ); Wed, 4 Jul 2007 19:22:27 -0400 Content-Disposition: inline In-Reply-To: <20070630092516.GD22050@infradead.org> Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Sat, Jun 30, 2007 at 10:25:16AM +0100, Christoph Hellwig wrote: > On Fri, Jun 29, 2007 at 03:21:30PM -0400, J. Bruce Fields wrote: > > From: J. Bruce Fields > > > > As Peter Staubach says elsewhere > > (http://marc.info/?l=linux-kernel&m=118113649526444&w=2): > > > > > The problem is that some file system such as NFSv2 and NFSv3 do > > > not have sufficient support to be able to support leases correctly. > > > In particular for these two file systems, there is no over the wire > > > protocol support. > > > > > > Currently, these two file systems fail the fcntl(F_SETLEASE) call > > > accidentally, due to a reference counting difference. These file > > > systems should fail more consciously, with a proper error to > > > indicate that the call is invalid for them. > > > > Define an nfs setlease method that just returns -EOPNOTSUPP. > > > > If someone can demonstrate a real need, perhaps we could reenable > > them in the presence of the "nolock" mount option. > > I'm not a big fan of default methods that do the wrong thing instead > of just missing functionality. Would you mind just returning > -EOPNOTSUPP if ->setlease is not implemented and add it to all > the local filesystems while all the network/distributed filesystems > should not have it, not just nfs. OK, I think that may make sense, but... wow does linux ever have a lot of obscure filesystems. This might take me a little longer. --b.