Method unallocated_read_mapping

block/src/qcow/metadata.rs:491–507

(
        &self,
        address: u64,
        count: usize,
        has_backing_file: bool,
    )

    }

    fn unallocated_read_mapping(
        &self,
        address: u64,
        count: usize,
        has_backing_file: bool,
    ) -> ClusterReadMapping {
        if has_backing_file {
            ClusterReadMapping::Backing {
                offset: address,
                length: count as u64,
            }
        } else {
            ClusterReadMapping::Zero {
                length: count as u64,
            }
        }
    }

    /// Maps a single cluster region for a sequential read.
    pub(crate) fn map_cluster_read(