dbAllocCtl
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
rc = dbAllocCtl(bmp, nblocks, l2nb, blkno, results);
static int dbAllocCtl(struct bmap * bmp, s64 nblocks, int l2nb, s64 blkno,