From mboxrd@z Thu Jan 1 00:00:00 1970 From: Matt Mackall Subject: Re: [RFC 11/26] tmpfs white-out support Date: Wed, 1 Aug 2007 21:48:12 -0500 Message-ID: <20070802024812.GN11166@waste.org> References: <20070730161323.100048969@weierstrass.suse.de> <20070730161324.160845468@weierstrass.suse.de> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Jan Blunck , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Bharata B Rao To: Hugh Dickins Return-path: Received: from waste.org ([66.93.16.53]:56967 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753374AbXHBCsE (ORCPT ); Wed, 1 Aug 2007 22:48:04 -0400 Content-Disposition: inline In-Reply-To: Sender: linux-fsdevel-owner@vger.kernel.org List-Id: linux-fsdevel.vger.kernel.org On Wed, Aug 01, 2007 at 04:13:46PM +0100, Hugh Dickins wrote: > On Mon, 30 Jul 2007, Jan Blunck wrote: > > > Introduce white-out support to tmpfs. > > > > Signed-off-by: Jan Blunck > > --- > > include/linux/shmem_fs.h | 1 > > mm/shmem.c | 54 +++++++++++++++++++++++++++++++++++++++++++++++ > > 2 files changed, 55 insertions(+) > > I see there's debate about whether this (and its fellows) give the > right semantic to whiteouts; and I've not begun to think about that. > > But as a patch to tmpfs for what you're trying to do, it looks just > about fine. I say "just about" because the reference counting looks > right, but I wouldn't dare say that it _is_ right without testing. > > And I'd probably want to add a minor adjustment, so that a mount with > nr_inodes=1000 could still support exactly 1000 inodes, despite your > allocating one for the whiteout (usually never used) at mount time. > But that can follow along later, no problem. Also, you might want to make sure whiteouts work with ramfs, which replaces tmpfs when tmpfs is disabled. -- Mathematics is the supreme nostalgia of our time.