BSD and derivate versions of Unix (such as SunOS, FreeBSD, NetBSD,
OpenBSD and NeXTstep) use a file system called UFS. Some System V
Unixes can create and mount hard disk partitions and diskettes using
this file system as well. Saying Y here will allow you to read from
these partitions; if you also want to write to them, say Y to the
experimental "UFS file system write support", below. Please read the
file <file:Documentation/admin-guide/ufs.rst> for more information.

The recently released UFS2 variant (used in FreeBSD 5.x) is
READ-ONLY supported.

Note that this option is generally not needed for floppies, since a
good portable way to transport files and directories between unixes
(and even other operating systems) is given by the tar program ("man
tar" or preferably "info tar").

When accessing NeXTstep files, you may need to convert them from the
NeXT character set to the Latin1 character set; use the program
recode ("info recode") for this purpose.

To compile the UFS file system support as a module, choose M here: the
module will be called ufs.

If you haven't heard about all of this before, it's safe to say N.

source code:

fs/ufs/