static fsw_status_t
fsw_hfsplus_bt_search(struct fsw_hfsplus_dnode *bt, /* in */ HFSPlusBTKey *sk, /* in */
                      k_cmp_t k_cmp, /* in */ BTNodeDescriptor *btnode, /* out */
                      fsw_u32 *rec_num /* out */)
{
    fsw_u32      node;
    fsw_u16      rec, lo, hi;
    HFSPlusBTKey *tk;
    int          cmp;
    fsw_status_t status;
    node = bt->bt_root;
    for (;;) {
        status = fsw_hfsplus_read(bt, (fsw_u64)node * bt->bt_ndsz,
                                  bt->bt_ndsz, btnode);
        if (status)
            return status;
        if ((void *)btnode + sizeof(BTNodeDescriptor) !=
            (void *)fsw_hfsplus_btnode_get_rec(btnode, bt->bt_ndsz, 0))
            return FSW_VOLUME_CORRUPTED;
        lo = 0;
        hi = fsw_u16_be_swap(btnode->numRecords) - 1;
        while (lo <= hi) {
             rec = (lo + hi) >> 1;
             tk = fsw_hfsplus_btnode_get_rec(btnode, bt->bt_ndsz, rec);
             cmp = k_cmp(tk, sk);
             if (cmp < 0)      // (tk < sk)
                 lo = rec + 1;
             else if (cmp > 0) // (tk > sk)
                 hi = rec - 1;
             else {            // (tk == sk)
                 if (btnode->kind != kBTLeafNode) {
                     hi = rec;
                     break;
                 }
                 *rec_num = rec;
                 return FSW_SUCCESS;
             }
        }
        if (btnode->kind != kBTIndexNode)
            break;
        tk = fsw_hfsplus_btnode_get_rec(btnode, bt->bt_ndsz, hi);
        node = fsw_hfsplus_bt_idx_get_child(tk);
    }
    return FSW_NOT_FOUND;
}