Inodes earlier than the 'first' inode (e.g.  journal, resize) should be
rejected early - except the root inode.  Also inode numbers that are too
big should be rejected early.

[akpm@osdl.org: cleanup]
Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>