EXT2_DBTOFSB
if (EXT2_DBTOFSB(&sblock, nblock) <= 0xffffffffffffULL) {
dp->e2di_nblock = h2fs32(EXT2_DBTOFSB(&sblock, nblock));
dp->e2di_nblock_high = h2fs16((EXT2_DBTOFSB(&sblock, nblock) >> 32));
bcount = EXT2_DBTOFSB(&sblock, fssize);
if (EXT2_DBTOFSB(fs, nblock) <= 0xffffffffffffULL) {
ip->i_e2fs_nblock = EXT2_DBTOFSB(fs, nblock) & 0xffffffff;
ip->i_e2fs_nblock_high = (EXT2_DBTOFSB(fs, nblock) >> 32) & 0xffff;