(unless someone tries to use libufs support functions without using
_fillout or _ctor to construct a uufsd.)
Obtained from: jmallett_libufs Perforce branch.
the build. It is here to compartmentalise functionality currently duplicated
in many notable programs in the base system. It currently handles block
reads and writes, as well as reading and writing of the filesystem superblock,
and the reading/lookup of inode data. It supports both UFS and UFS2. I
will be maintaining it, and porting programs to use it, however for now, it
is simply being built as part of world.