Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753899AbWKHCbY (ORCPT ); Tue, 7 Nov 2006 21:31:24 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1753909AbWKHCbY (ORCPT ); Tue, 7 Nov 2006 21:31:24 -0500 Received: from mx1.redhat.com ([66.187.233.31]:34688 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S1753899AbWKHCbY (ORCPT ); Tue, 7 Nov 2006 21:31:24 -0500 Date: Wed, 8 Nov 2006 02:30:39 +0000 From: Alasdair G Kergon To: "Rafael J. Wysocki" Cc: Eric Sandeen , Andrew Morton , linux-kernel@vger.kernel.org, dm-devel@redhat.com, Srinivasa DS Subject: Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex Message-ID: <20061108023039.GF30653@agk.surrey.redhat.com> Mail-Followup-To: "Rafael J. Wysocki" , Eric Sandeen , Andrew Morton , linux-kernel@vger.kernel.org, dm-devel@redhat.com, Srinivasa DS References: <20061107183459.GG6993@agk.surrey.redhat.com> <20061107122837.54828e24.akpm@osdl.org> <45510C73.7060408@redhat.com> <200611080005.50070.rjw@sisk.pl> <20061107234951.GD30653@agk.surrey.redhat.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20061107234951.GD30653@agk.surrey.redhat.com> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1213 Lines: 30 On Tue, Nov 07, 2006 at 11:49:51PM +0000, Alasdair G Kergon wrote: > I hadn't noticed that -mm patch. I'll take a look. swsusp-freeze-filesystems-during-suspend-rev-2.patch I think you need to give more thought to device-mapper interactions here. If an underlying device is suspended by device-mapper without freezing the filesystem (the normal state) and you issue a freeze_bdev on a device above it, the freeze_bdev may never return if it attempts any synchronous I/O (as it should). Try: while process generating I/O to filesystem on LVM issue dmsetup suspend --nolockfs (which the lvm2 tools often do) try your freeze_filesystems() Maybe: don't allow freeze_filesystems() to run when the system is in that state; or, use device-mapper suspend instead of freeze_bdev directly where dm is involved; or skip dm devices that are already frozen - all with appropriate dependency tracking to process devices in the right order. Alasdair -- agk@redhat.com - 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/