Change function in fs/ufs/dir.c and fs/ufs/namei.c to work with pages
instead of straight work with blocks.  It fixed such bugs:

* for i in `seq 1 1000`; do touch $i; done - crash system
* mkdir create directory without "." and ".." entries
Signed-off-by: NEvgeniy Dushistov <dushistov@mail.ru>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>