Re: oops when removing sbp2 module

[Patrick Mansfield <patmans@us.ibm.com>]

On Sun, Oct 05, 2003 at 11:12:18PM +1000, Paul Mackerras wrote:

> In fact what is happening is that class_device_unregister gets called
> twice for the same classdev.  This is because scsi_remove_device gets
> called twice for the same device.  The first time, the call chain
> looks like this:
>
> scsi_remove_device
> sbp2_remove_device
> sbp2_remove
> device_release_driver
> driver_detach
> bus_remove_driver
> driver_unregister
> hpsb_unregister_protocol
> sbp2_module_exit
> 
> and the second time it looks like this:
> 
> scsi_remove_device
> scsi_forget_host
> scsi_remove_host
> sbp2_remove_host
> hpsb_unregister_highlevel
> sbp2_module_exit
> 
> So, is this a reference counting problem on the classdev, a problem
> where the scsi layer doesn't remove the scsi device from its internal
> lists properly in scsi_remove_device, or a problem in the sbp2 code?
> Anyone got a fix?
> 
> Thanks,
> Paul.

Paul -

There is a typo on a change to the access_count check. 

Try this patch:

--- bleed-2.5/drivers/scsi/scsi_sysfs.c-orig	Mon Sep 29 12:21:09 2003
+++ bleed-2.5/drivers/scsi/scsi_sysfs.c	Mon Sep 29 16:19:22 2003
@@ -412,7 +412,7 @@
 		set_bit(SDEV_DEL, &sdev->sdev_state);
 		if (sdev->host->hostt->slave_destroy)
 			sdev->host->hostt->slave_destroy(sdev);
-		if (atomic_read(&sdev->access_count))
+		if (!atomic_read(&sdev->access_count))
 			device_del(&sdev->sdev_gendev);
 		up_write(&class->subsys.rwsem);
 	}

-- Patrick Mansfield