Return-Path: Received: from fieldses.org ([174.143.236.118]:37213 "EHLO fieldses.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932233Ab1FJNtC (ORCPT ); Fri, 10 Jun 2011 09:49:02 -0400 Date: Fri, 10 Jun 2011 09:48:59 -0400 From: "J. Bruce Fields" To: Volker Lendecke Cc: linux-nfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, samba-technical@lists.samba.org, Casey Bodley Subject: Re: [PATCH] locks: breaking read lease should not block read open Message-ID: <20110610134859.GA27837@fieldses.org> References: <20110609231606.GB22215@fieldses.org> Content-Type: text/plain; charset=us-ascii In-Reply-To: Sender: linux-nfs-owner@vger.kernel.org List-ID: MIME-Version: 1.0 On Fri, Jun 10, 2011 at 09:56:49AM +0200, Volker Lendecke wrote: > On Thu, Jun 09, 2011 at 07:16:06PM -0400, J. Bruce Fields wrote: > > The lease code behavior during the lease-breaking process is strange. > > Fixing it completely would be complicated by the fact that the current > > code allows a lease break to downgrade the lease instead of necessarily > > removing it. > > > > But I can't see what the point of that feature is. And googling around > > and looking at the Samba code, I can't see any evidence that anyone uses > > it. Think we could just do away with removing the ability to downgrade > > to satisfy a lease break? > > Without having looked too deeply, just let me point out that > Samba here has a plain flaw. Early Linux Kernel versions > that we programmed against did not properly support read > only leases, so we did not implement that initially. If I > remember correctly we never got around to finally do it once > it became available. Eventually we will probably, as read > only leases are a pretty important feature to present to > CIFS clients. Thanks, I didn't know that. (Or I did, and I forgot.) When you *do* implement that, is there any chance you'd have this need to be able to downgrade to a read lease in the case of a conflict? --b.