Re: [PATCH] libata: fix use-after-free during driver unload/unplug

[Jeff Garzik <jgarzik@pobox.com>]

Mark Lord wrote:
> Hi Jeff!
> 
> Jeff Garzik wrote:
> 
>>
>> * add ->host_stop_prewalk() hook, use it in sata_qstor.c (hi Mark). 
>> sata_qstor appears to require the host-stop-before-port-stop ordering 
>> that existed prior to applying the attached patch.
> 
> 
> Mmm.. I'm a little bit rusty here, but I don't think qstor
> cares about the order, so long as ports are marked with
> ATA_FLAG_PORT_DISABLED before invoking port_stop().
> 
> I've tried to allow disabling/enabling individual ports
> on-the-fly as needed, even though it never really happens
> in practice.  So host_stop() kills the whole chip, whereas
> port_stop() I took to mean just one of the four SATA ports.

qstor's ->host_stop() disables global interrupts, and I didn't know if 
you really wanted to do that prior to ->port_stop().

I would much prefer to eliminate the ->host_stop_prewalk() hook, and 
simply call ->host_stop after all ->port_stop() calls complete, if qstor 
doesn't need the pre-walk.

	Jeff