These are a few places I've found in jbd that look like they may not be
16T-safe, or consistent with the use of unsigned longs for block
containers.  Problems here would be somewhat hard to hit, would require
journal blocks past the 8T boundary, which would not be terribly common.
Still, should fix.

(some of these have come from the ext4 work on jbd as well).

I think there's one more possibility that the wrap() function may not be
safe IF your last block in the journal butts right up against the 232 block
boundary, but that seems like a VERY remote possibility, and I'm not
worrying about it at this point.

Signed-off-by: Eric Sandeen <esandeen@redhat.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>