"The ongoing discussion about the Reiser4 filesystem continues
on the lkml. Jeff Garzik discussed the complexity introduced by a
plugin layer, suggesting it is really a second VFS, 'furthermore,
it completely changes the notion of what a Linux filesystem is.
Currently, each Linux filesystem is a tightly constrained set of
metadata support. reiser4 changes 'tightly constrained' to
'infinity'. While that freedom is certainly liberating, it also has
obvious support costs due to new admin paradigms and customer