From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932097AbXKOT1L (ORCPT ); Thu, 15 Nov 2007 14:27:11 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759580AbXKOT04 (ORCPT ); Thu, 15 Nov 2007 14:26:56 -0500 Received: from pentafluge.infradead.org ([213.146.154.40]:60792 "EHLO pentafluge.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751026AbXKOT0z (ORCPT ); Thu, 15 Nov 2007 14:26:55 -0500 Date: Thu, 15 Nov 2007 11:23:19 -0800 From: Greg KH To: Jiri Kosina Cc: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.24-rc2-mm1 Message-ID: <20071115192319.GA30186@kroah.com> References: <20071113175906.497a1a6a.akpm@linux-foundation.org> <20071114083906.178232cb.akpm@linux-foundation.org> <20071114181948.GA15240@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20071114181948.GA15240@kroah.com> User-Agent: Mutt/1.5.16 (2007-06-09) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Nov 14, 2007 at 10:19:48AM -0800, Greg KH wrote: > On Wed, Nov 14, 2007 at 06:02:07PM +0100, Jiri Kosina wrote: > > On Wed, 14 Nov 2007, Jiri Kosina wrote: > > > > > > I'd suspect the driver tree. I think I'll need to do a quick -mm2 > > > > without that tree present. > > > I am just verifying whether reverting kset changes fixes this, will let > > > you know soon. > > > > OK, so I reverted > > gregkh-driver-kset-convert-block_subsys-to-use-kset_create (which made me > > also revert gregkh-driver-kobject-remove-subsystem_register-functions and > > gregkh-driver-kset-remove-decl_subsys-macro so that we compile). Both the > > error message from lockdep and more importantly the spinlock lockup have > > gone, and the system with these patches reverted boots for me fine. > > > > Well not that fine, I still see (which is the same backtrace that caused > > the lockup with plain -rc2-mm1, but doesn't make the machine hang): > > > > floppy0: Floppy io-port 0x03f2 in use > > WARNING: at lib/kref.c:33 kref_get() > > > > Call Trace: > > [] kobject_add+0x9b/0x197 > > [] kref_get+0x2f/0x36 > > [] kobject_get+0x12/0x17 > > [] kobject_add+0xad/0x197 > > [] register_disk+0x48/0x205 > > [] add_disk+0x34/0x3d > > [] rd_init+0x172/0x1e1 > > [] kernel_init+0x175/0x2e6 > > [] trace_hardirqs_on+0x115/0x139 > > [] trace_hardirqs_on_thunk+0x35/0x3a > > [] trace_hardirqs_on+0x115/0x139 > > [] child_rip+0xa/0x12 > > [] restore_args+0x0/0x30 > > [] kernel_init+0x0/0x2e6 > > [] child_rip+0x0/0x12 > > someone is trying to call kref_get on a kobject that has not been > initialized yet, which could be the reason the newer patches break > something, as the pointers are not set up properly with a call to > kobject_init() first. > > But, alloc_disk() should have been called on this gendisk for it to work > properly at all, unless something is trashing that structure? > > I'm way confused... This patch, as found by Dave Young, should fix the issue: I'll roll it into my larger patchset so that Andrew will get it automatically next release, but here it is for people to use now. thanks, greg k-h -------------- From: Greg Kroah-Hartman Subject: fix bug with adding new block devices in -mm need to set the kset before initializing the kobject. --- block/genhd.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/block/genhd.c +++ b/block/genhd.c @@ -718,9 +718,9 @@ struct gendisk *alloc_disk_node(int mino } } disk->minors = minors; - kobject_init(&disk->kobj); disk->kobj.kset = block_kset; disk->kobj.ktype = &ktype_block; + kobject_init(&disk->kobj); rand_initialize_disk(disk); INIT_WORK(&disk->async_notify, media_change_notify_thread);