> One way to look at that issue is to ask what user mode notifications
> will be used to address that part of the hotplug problem.  Devfsd
> is what some folk like, but it's not universally accepted.  GUI
> driven solutions don't seem right in all cases either.

devfsd is at least already here. The existing /sbin/hotplug architecture
can't handle it. A new kind of event would be needed.
Even so, you'll probably won't make the user happy if it works only
on plugging in and not when he puts in a new medium.
A look at supermount might be in order.

> As I understand things, USB-to-SCSI adapters (like most usb-storage
> devices) will also have "bus" add/remove events to deal with.  Likewise
> with cases like hotplugging a SCSI controller on a Cardbus laptop, or on a
> CompactPCI (or HotplugPCI) enterprise level server.  Presumably those cases
> aren't as troublesome?

Yes, a new bus is scanned anyway.
To a certain extent the notion of bus vs. device becomes moot, when devices
are identified by globally unique numbers. Should a fibre channel drive be 
given other names if it's shifted to another controller ?

To let deeds follow words I've attached a patch that adds error reporting and 
locking to the bus removal functions.

	Regards
		Oliver