static int64_t coroutine_fn qcow2_co_get_block_status(BlockDriverState *bs,
        int64_t sector_num, int nb_sectors, int *pnum)
{
    BDRVQcowState *s = bs->opaque;
    uint64_t cluster_offset;
    int index_in_cluster, ret;
    int64_t status = 0;

    *pnum = nb_sectors;
    qemu_co_mutex_lock(&s->lock);
    ret = qcow2_get_cluster_offset(bs, sector_num << 9, pnum, &cluster_offset);
    qemu_co_mutex_unlock(&s->lock);
    if (ret < 0) {
        return ret;
    }

    if (cluster_offset != 0 && ret != QCOW2_CLUSTER_COMPRESSED &&
        !s->crypt_method) {
        index_in_cluster = sector_num & (s->cluster_sectors - 1);
        cluster_offset |= (index_in_cluster << BDRV_SECTOR_BITS);
        status |= BDRV_BLOCK_OFFSET_VALID | cluster_offset;
    }
    if (ret == QCOW2_CLUSTER_ZERO) {
        status |= BDRV_BLOCK_ZERO;
    } else if (ret != QCOW2_CLUSTER_UNALLOCATED) {
        status |= BDRV_BLOCK_DATA;
    }
    return status;
}
Unknown