From mboxrd@z Thu Jan 1 00:00:00 1970 From: James Bottomley Subject: Subtle but oops causing problem with class_device->device conversion Date: Tue, 29 Jul 2008 12:42:28 -0500 Message-ID: <1217353348.6103.20.camel@localhost.localdomain> Mime-Version: 1.0 Content-Type: text/plain Content-Transfer-Encoding: 7bit Return-path: Received: from accolon.hansenpartnership.com ([76.243.235.52]:53980 "EHLO accolon.hansenpartnership.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760202AbYG2Rm4 (ORCPT ); Tue, 29 Jul 2008 13:42:56 -0400 Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Kay Sievers , Hannes Reinecke Cc: linux-scsi , linux-kernel It's taken me a while to track this down. Basically there's an oops in scsi_transport_spi that's directly caused by this. What happened is that you made all class devices become real devices and be parented to devices they were formerly allied to through the class device dev pointer. This means that effectively you expanded the child list of every device to include not only its real children but also its class devices. This breaks in device_for_each_child *if* the routine in the iterator doesn't perform checks on the devices it gets back (scsi_transport_spi was assuming that every device it got was embedded in a struct scsi_device because they're the only logical children of a scsi_target). I can fix the SCSI breakage, but the whole tree will need auditing to check that nothing else is using this assumption. James