No, they haven't.
> 1. Do the bits of the block bitmaps represent logial blocks or
> fragments?
Umm.. Hard to say for sure, seems to be logical blocks of
1kB (or 2kB, or 4kB) Those are also fragment-size parameters,
though fragments are not used.
> 2. How do you set the fragment size within a filesystem?
See e2mkfs utility. It creates the initial superblock,
where that info is stored.
> 3. What source code deals with the implementation of fragments?
None. What would is balloc.c
> Thanks :)
> --
> Scott Gray
/Matti Aarnio <matti.aarnio@tele.fi>