DW:

DW:
 - We have to test the bit before calling file_map_bit_reset.
   file_map_bit_reset doesn't do bounds checking.  It assumes
   filn is a valid file number, but it might not be because
   the map is dynamic in size.  Also clearing an already clear
   bit puts the map counter of-of-whack.  Damn, been looking
   for that bug for a long time.

- gindent for good measure.