BT_LEVEL1
nbp = getdatablk(indirblk, sblock.fs_bsize, BT_LEVEL1);
case BT_LEVEL1:
ret = iblock(idesc, remsize, BT_LEVEL1 + i);
bp = getdatablk(blk, sblock.fs_bsize, BT_LEVEL1 + level);
bp = getdatablk(blk, fs->fs_bsize, BT_LEVEL1 + level);
bp = getdatablk(blk, fs->fs_bsize, BT_LEVEL1 + level);
bp = getdatablk(blkno, fs->fs_bsize, BT_LEVEL1 + level);