timeout()/untimeout() API:
- Clients supply callout handle storage, thus eliminating problems of
resource allocation.
- Insertion and removal of callouts is constant time, important as
this facility is used quite a lot in the kernel.
The old timeout()/untimeout() API has been removed from the kernel.
so that the right entries get added to dev_name2blk[]. Needed for / on RAID.
(Missed these yesterday.. Thanks to Izumi Tsutsui for noticing, and for
letting me know :) )