xfs: widen btree maxlevels computation to handle 64-bit record counts

Rework xfs_btree_compute_maxlevels to handle larger record counts, since
we're about to add support for very large indices for the realtime rmap
btree.  We also need this to compute the theoretical maximum number of
inodes that can be stored in a 1TB AG with 256 byte inodes.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2 files changed