Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753382AbXKWX3w (ORCPT ); Fri, 23 Nov 2007 18:29:52 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752132AbXKWX3n (ORCPT ); Fri, 23 Nov 2007 18:29:43 -0500 Received: from ogre.sisk.pl ([217.79.144.158]:58715 "EHLO ogre.sisk.pl" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752048AbXKWX3m (ORCPT ); Fri, 23 Nov 2007 18:29:42 -0500 From: "Rafael J. Wysocki" To: Jeremy Fitzhardinge Subject: Re: freeze vs freezer Date: Sat, 24 Nov 2007 00:47:21 +0100 User-Agent: KMail/1.9.6 (enterprise 20070904.708012) Cc: David Chinner , xfs-masters@oss.sgi.com, Linux Kernel Mailing List References: <4744FD87.7010301@goop.org> In-Reply-To: <4744FD87.7010301@goop.org> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200711240047.21624.rjw@sisk.pl> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2070 Lines: 47 On Thursday, 22 of November 2007, Jeremy Fitzhardinge wrote: > It seems that a process blocked in a write to an xfs filesystem due to > xfs_freeze cannot be frozen by the freezer. The freezer doesn't handle tasks in TASK_UNINTERRUPTIBLE and I don't know how to make it handle them without at least partially defeating its purpose. > I see this if I suspend my laptop while doing something xfs-filesystem > intensive, like a kernel build. My suspend scripts freeze the XFS > filesystem (as Dave said I should), which presumably blocks some writer, > and then the freezer times out and fails to complete. > > Here's part of the process dump the freezer does when it times out: > > cc1 D 00000000 0 18138 18137 > dd5f1e24 00200082 00000002 00000000 ecdeeb00 ecdeec64 c200f280 00000001 > 009c09a0 dd5f1e0c dd5f1e0c 0000000f 00000000 00000000 00000000 dd5f1e74 > c7beb480 dd5f1e88 dd5f1ea8 c0228d97 e8889540 dd5f1e38 c015b75d dd5f1e44 > Call Trace: > [] xfs_write+0xf4/0x6d9 > [] xfs_file_aio_write+0x53/0x5b > [] do_sync_write+0xae/0xec > [] vfs_write+0xa4/0x120 > [] sys_write+0x3b/0x60 > [] sysenter_past_esp+0x6b/0xa1 > ======================= > > > I haven't looked at how to fix this yet. I only just worked out why I > was getting suspend failures. Well, you can add freezer_do_not_count()/freezer_count() annotations to xfs_write() (and whatever else is blocked as a result of the XFS being frozen). Generally, that would be risky without the freezing of XFS, however, because it might leak us filesystem data to a storage device after creating a hibernation image which would result in the filesystem corruption after the resume. Still, if you only suspend to RAM, that should be safe. Greetings, Rafael - 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/