On Wed, Jun 27 2001, Jens Axboe wrote:
> > I can see one mm corruption race condition in the patch, you missed
> > nested irq in the for kmap_irq_bh (PIO).  You must _always_
> > __cli/__save_flags before accessing the KMAP_IRQ_BH slot, in case the
> > remapping is required (so _only_ when the page is in the highmem zone).
> > Otherwise memory corruption will happen when the race triggers (for
> > example two ide disks in PIO mode doing I/O at the same time connected
> > to different irq sources).
> 
> Ah yes, my bad. This requires some moving around, I'll post an updated
> patch later tonight. Thanks!

A prelim and untested fix just whipped up

-- 
Jens Axboe