Book on FFS

[Edgar Fuß]

Is there a book (or other documentation) about FFS giving more details than the 4.4BSD bible?

I'm writing a Perl script that takes a subset of newfs's arguments, reads a find -ls output and computes the fragmentation/bookkeeping overhead for that particular data set. (The intent is to find out how much the newfs parameters actually matter in terms of overhead for that given data set.)

In the course of researching what the exact overhead for the free list, inodes and CG heads is, I learned (from discussions on NetBSD's tech-kern list and from reading ufs/ffs/fs.h and mkfs.c) various "interesting" things like files that need indirect blocks not being allocated fragments, "number of blocks" and "number of data blocks" (i.e. fs_size and fs_dsize) being in units of fragments, not blocks. I suspect there is way more for me to learn in this field.