BM_BIT_TO_SECT
#define BM_SECT_PER_BIT BM_BIT_TO_SECT(1)
#define DRBD_MAX_SECTORS_FLEX BM_BIT_TO_SECT(0xffff7fff)
BM_BIT_TO_SECT(device->rs_total - 1);
BM_BIT_TO_SECT(drbd_bm_bits(device) - device->ov_left);
sector = BM_BIT_TO_SECT(bit);