ffs softdeps fix request

[Alfred Perlstein]

There's an artifact of ffs softupdates that causes issues if a crash
occurs while deleting or creating files.

Basically, one can wind up with a directory that is empty, but the
link count is artificially high.  Then you can have a directory
that is empty, but not removeable.  It would be somewhat trivial
to add some code to check the directory's contents when a VOP_RMDIR
would have failed because of the link count check.

But then my head went all explody when trying to figure out how
that would impact the background fsck in progress.

Any ideas?

-- 
- Alfred Perlstein
- Research Engineering Development Inc.
- email: bright at mu.org cell: 408-480-4684