Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753793AbYJaEZP (ORCPT ); Fri, 31 Oct 2008 00:25:15 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751353AbYJaEZA (ORCPT ); Fri, 31 Oct 2008 00:25:00 -0400 Received: from yw-out-2324.google.com ([74.125.46.29]:61924 "EHLO yw-out-2324.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750997AbYJaEY7 (ORCPT ); Fri, 31 Oct 2008 00:24:59 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=message-id:date:from:sender:to:subject:cc:in-reply-to:mime-version :content-type:content-transfer-encoding:content-disposition :references:x-google-sender-auth; b=uVWL/FIWMTObQ6GnJvJx9xpNyMNUkoCzLFVPUr60NUlDEWvFOP8/AhVMSPgsHspQ/+ uVfR5Mq94YTvgcHcexffDRPitgVSOnEMhJEuN1Ne5WdmfopaLmrvujgPCP3S2Jhbkbrs ubz0ihpXBvecoqtmh6aLw5U1/sBx667QKk85s= Message-ID: <386072610810302124x6b3bdcfby41f37941017f2ee7@mail.gmail.com> Date: Fri, 31 Oct 2008 12:24:58 +0800 From: "Bryan Wu" To: "Kay Sievers" Subject: Re: 2.6.28-rc2: (mtd)block/partitions BUG with kobject reference count Cc: "Peter Korsgaard" , "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=ISO-8859-1 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> X-Google-Sender-Auth: b3bf48bde0f9b80a Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2584 Lines: 63 On Fri, Oct 31, 2008 at 7:47 AM, Kay Sievers wrote: > 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); IMHO, this is a workaround, right? I think the final solution should provide every 'gendisk' a dedicated 'bdi'. So they won't mess up and overwrite. -Bryan -- 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/