ISNULLDSTARTBLOCK 1841 fs/xfs/xfs_bmap_btree.c ASSERT((b >> 32) == 0 || ISNULLDSTARTBLOCK(b)); ISNULLDSTARTBLOCK 1917 fs/xfs/xfs_bmap_btree.c ASSERT((b >> 32) == 0 || ISNULLDSTARTBLOCK(b));