Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756965AbYF3GMc (ORCPT ); Mon, 30 Jun 2008 02:12:32 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752695AbYF3GMX (ORCPT ); Mon, 30 Jun 2008 02:12:23 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:39184 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752670AbYF3GMW (ORCPT ); Mon, 30 Jun 2008 02:12:22 -0400 Date: Mon, 30 Jun 2008 02:11:50 -0400 From: Christoph Hellwig To: "Rafael J. Wysocki" Cc: Dave Chinner , xfs-masters@oss.sgi.com, Elias Oltmanns , Henrique de Moraes Holschuh , Kyle Moffett , Matthew Garrett , David Chinner , Jeremy Fitzhardinge , Linux Kernel Mailing List , Jens Axboe Subject: Re: [xfs-masters] Re: freeze vs freezer Message-ID: <20080630061149.GA352@infradead.org> References: <4744FD87.7010301@goop.org> <20080626150910.GK5642@ucw.cz> <20080629221217.GM29319@disturbed> <200806300122.48204.rjw@sisk.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200806300122.48204.rjw@sisk.pl> User-Agent: Mutt/1.5.18 (2008-05-17) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1231 Lines: 28 On Mon, Jun 30, 2008 at 01:22:47AM +0200, Rafael J. Wysocki wrote: > > > Actually, I believe requirements are same. > > > > > > 'don't do i/o in dangerous period'. > > > > > > swsusp will just do sync() before entering dangerous period. That > > > provides consistent-enough state... > > > > As I've said many times before - if the requirement is "don't do > > I/O" then you have to freeze the filesystem. In no way does 'sync' > > prevent filesystems from doing I/O..... > > Well, it seems we can handle this on the block layer level, by temporarily > replacing the elevator with something that will selectively prevent fs I/O > from reaching the layers below it. > > I talked with Jens about it on a very general level, but it seems doable at > first sight. Why would you hack the blok layer when we already have a perfectly fine facility to archive what you want? freeze_bdev is there exactly for the purpose to make the filesystem consistant on disk and then freeze all I/O. -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/