File space allocation/deallocation under Unix (BSD4.x)

[Guy Harris]

> I just looked at the directory /usr/spool/news/.rnews on our BSD 4.3 system,
> and it was only 512 bytes long, so there must be some space reclaiming going
> on (after a news problem 1500 articles were queued last week)

This is true.  4.3BSD will reclaim empty space at the end of a directory when
you create a new entry in the directory.  (One benefit of this, as you
discovered, is that it reclaims space in huge spool directories....)