xfs_btree_readahead
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);
xfs_btree_readahead(cur, lev, XFS_BTCUR_RIGHTRA);
xfs_btree_readahead(cur, level, XFS_BTCUR_LEFTRA);
xfs_btree_readahead(cur, lev, XFS_BTCUR_LEFTRA);
xfs_btree_readahead(cur, level, XFS_BTCUR_RIGHTRA);