Unfortunately, the following statement is not true:

	If no file systems are given to fsck_ffs then a default list of
	file sys- tems is read from the file /etc/fstab.

To test, boot single user and run
	# fsck_ffs -fp

If fsck_ffs is *supposed* to read /etc/fstab like fsck does, then the
problem is in the code.

Also the `-p` option (preen) is not in the list of options.

Sorry for not attaching a patch. The disk I just lost had my source
tree and I'm not done rebuilding/recovering the system.

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