From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751540AbaEZBTK (ORCPT ); Sun, 25 May 2014 21:19:10 -0400 Received: from ipmail06.adl6.internode.on.net ([150.101.137.145]:26897 "EHLO ipmail06.adl6.internode.on.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751401AbaEZBTJ (ORCPT ); Sun, 25 May 2014 21:19:09 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: AlxMAC+VglN5LL1sPGdsb2JhbABZgwdSjXOcWgEBAQEBAQaQUIc6AYEGFwMBAQEBODWCJQEBAQQBAiQTHCMQCAMYCSUPBQ0HEQMHGhOILgMQDtENDYYaFxaFP4ZnghYHhEAElXKBIGuBdYsYgh6JPCsv Date: Mon, 26 May 2014 11:19:04 +1000 From: Dave Chinner To: Linus Torvalds Cc: Plamen Petrov , LKML , xfs@oss.sgi.com Subject: Re: [PATCH] do_mounts: try all available filesystems before panicking Message-ID: <20140526011904.GT8554@dastard> References: <1399314889-9829-1-git-send-email-plamen.sisi@gmail.com> <20140526000813.GS8554@dastard> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20140526000813.GS8554@dastard> User-Agent: Mutt/1.5.21 (2010-09-15) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, May 26, 2014 at 10:08:13AM +1000, Dave Chinner wrote: > On Sun, May 25, 2014 at 01:04:09PM -0700, Linus Torvalds wrote: > > On Mon, May 5, 2014 at 11:34 AM, Plamen Petrov wrote: > > > > > > The story short: on systems with btrfs root I have a kernel .config with ext4, > > > xfs and btrfs built-in which works fine with 3.13.x, but 3.14.x panics. After > > > inserting some debug printks, I got this info from mount_block_root: > > > > > > ---> EACCESS=13, EINVAL=22, Available filesystems: ext3 ext2 ext4 fuseblk xfs btrfs > > > -----> Tried ext3, error code is -22. > > > -----> Tried ext2, error code is -22. > > > -----> Tried ext4, error code is -22. > > > -----> Tried fuseblk, error code is -22. > > > -----> Tried xfs, error code is -38. > > > VFS: Cannot open root device "sda2" or unknown-block(8,2): error -38 > > > Please append a correct "root=" boot option; here are the available partitions: BTW, This is the original thread with lots of triage in it: http://www.spinics.net/lists/linux-btrfs/msg33455.html But that doesn't reach any conclusion. I suspect that the change of btrfs init (from very early (@~1.8s into the boot) until a few milliseconds before the root mount is changing the order in which the filesystem type list is traversed by the mount, resulting in XFS being used to probe the device before btrfs. Why XFS is seeing /dev/sda2 as containing an XFS filesystem is not yet clear, but perhaps once you've dumped the the first sector of the btrfs partition all will become clear.... Cheers, Dave. -- Dave Chinner david@fromorbit.com