From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Re: BUG in: Driver core: convert block from raw kobjects to core devices (fwd) Date: Wed, 31 Oct 2007 10:15:01 -0500 Message-ID: <1193843701.3411.20.camel@localhost.localdomain> References: <1193685197.2321.9.camel@lov.site> <20071031042531.GB16426@kroah.com> <1193827590.2423.42.camel@lov.site> <20071031143255.GC7076@kroah.com> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from hancock.steeleye.com ([71.30.118.248]:55101 "EHLO hancock.sc.steeleye.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1754010AbXJaPPD (ORCPT ); Wed, 31 Oct 2007 11:15:03 -0400 In-Reply-To: <20071031143255.GC7076@kroah.com> Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Greg KH Cc: Kay Sievers , Alan Stern , Hannes Reinecke , SCSI development list On Wed, 2007-10-31 at 07:32 -0700, Greg KH wrote: > Hm, I seem to have missed the part in this thread where someone said > that it was valid to have a parent reference a child device. That's > just wrong and needs to be fixed. Is that in the scsi layer somewhere? > The block layer? It sure isn't in the driver core... This is the piece I'm still not clear on. It's something to do with the gendisk. I'd have to look in block, but I believe the queue takes a ref to the gendisk. The scsi_device has a ref to the queue and the scsi_disk (in sd) has a ref to both the scsi_device and the gendisk. That means, until sd is unbound and the scsi_disk released, there's an implied unbreakable reference chain. at least, I think that's what the problem is. James