"rm" command, on file system with "ufs1" type cause system hang up.  This
is, in fact, not so bad as it seems to be, because of after that in "kernel
control path" there are 3-4 places which may cause "oops".

So the first patch fix oopses, and the second patch fix "kernel hang up".

"oops" appears because of reading of group's summary info partly wrong, and
access to not first group's summary info cause "oops".
Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>