[PATCH] ufs: zero metadata

Presently if we allocate several "metadata" blocks (pointers to indirect
blocks for example), we fill with zeroes only the first block.  This cause
some problems in "truncate" function.  Also this patch remove some unused
arguments from several functions and add comments.

Signed-off-by: Evgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>