lkml.org 
[lkml]   [2008]   [Jul]   [29]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
SubjectRe: Subtle but oops causing problem with class_device->device conversion
From
Date
On Tue, 2008-07-29 at 19:59 +0200, Kay Sievers wrote:
> On Tue, 2008-07-29 at 12:42 -0500, James Bottomley wrote:
> > 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.
>
> I guess it's caused by:
> [SCSI] add scsi_host and scsi_target to scsi_bus
>
> This patch implements scsi_host and scsi_target device types
> and adds both to the scsi_bus.
> http://git.kernel.org/?p=linux/kernel/git/torvalds/linux-2.6.git;a=commitdiff;h=b0ed43360fdca227048d88a08290365cb681c1a8
>
> and not by the re-parenting, so it should be limited to SCSI, right?

No .. read the email. It's caused by adding extra children to the
device via the class_device conversion. device_for_each_child doesn't
care what the type is (although that might be a potential generic fix
for this).

So, it's definitely not confined to SCSI.

James




\
 
 \ /
  Last update: 2008-07-29 20:09    [W:0.325 / U:0.008 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site