Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754991AbYJ3Xrh (ORCPT ); Thu, 30 Oct 2008 19:47:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756167AbYJ3XrV (ORCPT ); Thu, 30 Oct 2008 19:47:21 -0400 Received: from qb-out-0506.google.com ([72.14.204.228]:2278 "EHLO qb-out-0506.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755782AbYJ3XrU (ORCPT ); Thu, 30 Oct 2008 19:47:20 -0400 Message-ID: Date: Fri, 31 Oct 2008 00:47:18 +0100 From: "Kay Sievers" To: "Peter Korsgaard" Subject: Re: 2.6.28-rc2: (mtd)block/partitions BUG with kobject reference count Cc: "Rafael J. Wysocki" , linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org In-Reply-To: MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <87ej1z4ep8.fsf@macbook.be.48ers.dk> <200810300027.19116.rjw@sisk.pl> <87abcnj810.fsf@macbook.be.48ers.dk> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2288 Lines: 56 On Thu, Oct 30, 2008 at 22:51, Kay Sievers wrote: > On Thu, Oct 30, 2008 at 00:28, Peter Korsgaard wrote: >>>>>>> "Rafael" == Rafael J Wysocki writes: >> >> Rafael> On Wednesday, 29 of October 2008, Peter Korsgaard wrote: >> >> Hi, >> >> >> >> I'm seing what looks like a kobject reference count issue with >> >> mtdblock_ro + mtd_dataflash + mtd partitions and repeated unbind/bind. >> >> I'm on 2.6.28-rc2, but I can reproduce the problem on 2.6.27 as well. >> >> Rafael> Is it reproducible with 2.6.26 too? >> >> Sorry, I haven't backported my platform support code to such "old" >> kernel. I can do it though, if you think it will help pinpoint the >> issue. > > This sounds like a possible reason for the problem: > "After digging into the mtd code, this bug is not related to our driver. It > should be a subtle bug in mtd core code. > > In add_mtd_partition, for 2 partitions, 2 gendisk structures will be > allocated. But these 2 gendisk->queue will be set to the same > request_queue. Then when unregistering the 1st partition, from the > same request_queue->backing_dev_info, the bdi struct will be set to > NULL. So for the 2nd partition (bdi == NULL), the sysfs dir of 2nd > partition will not be removed. Finally, when modprobe the module > again, the 2nd partition won't be added" > https://blackfin.uclinux.org/gf/tracker/4463 Looks like a bdi issue: http://lkml.org/lkml/2008/10/30/519 Peter, if I do this (whitespace mangled, just pasted in here), the error goes away for me. Can you try this? Thanks, Kay --- a/block/genhd.c +++ b/block/genhd.c @@ -515,7 +515,8 @@ void add_disk(struct gendisk *disk) blk_register_queue(disk); bdi = &disk->queue->backing_dev_info; - bdi_register_dev(bdi, disk_devt(disk)); + if (!bdi->dev) + bdi_register_dev(bdi, disk_devt(disk)); retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, "bdi"); WARN_ON(retval); -- 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/