From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934601AbXHAPOz (ORCPT ); Wed, 1 Aug 2007 11:14:55 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S933650AbXHAPOk (ORCPT ); Wed, 1 Aug 2007 11:14:40 -0400 Received: from extu-mxob-2.symantec.com ([216.10.194.135]:21462 "EHLO extu-mxob-2.symantec.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S933270AbXHAPOj (ORCPT ); Wed, 1 Aug 2007 11:14:39 -0400 Date: Wed, 1 Aug 2007 16:13:46 +0100 (BST) From: Hugh Dickins X-X-Sender: hugh@blonde.wat.veritas.com To: Jan Blunck cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, Bharata B Rao Subject: Re: [RFC 11/26] tmpfs white-out support In-Reply-To: <20070730161324.160845468@weierstrass.suse.de> Message-ID: References: <20070730161323.100048969@weierstrass.suse.de> <20070730161324.160845468@weierstrass.suse.de> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Brightmail-Verdict: VlJEQwAAAAIAAAABAAAAAAAAAAEAAAAAAAAABGluYm94AGxpbnV4LWZzZGV2ZWxAdmdlci5rZXJuZWwub3JnAGxpbnV4LWtlcm5lbEB2Z2VyLmtlcm5lbC5vcmcAamJsdW5ja0BzdXNlLmRlAGJoYXJhdGFAbGludXgudm5ldC5pYm0uY29tAA== X-Brightmail-Tracker: AAAAAA== Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org 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. Hugh