153     /* the L1 position has not yet been updated, so these clusters must  in qcow2_grow_l1_table()
384  * the same type starting from @sc_from. Compressed clusters are
436  * At most @nb_clusters are checked (note that this means clusters,
438  * Compressed clusters are always processed one by one but for the
469                 /* Compressed clusters are always processed one by one */  in count_contiguous_subclusters()
513      * bdrv_check_qiov_request(), and aligning requests to clusters never  in do_perform_cow_read()
582  * Compressed clusters are always processed one by one.
873     /* compressed clusters never have the copied flag */  in qcow2_alloc_compressed_cluster_offset()
1110      * Don't discard clusters that reach a refcount of 0 (e.g. compressed  in qcow2_alloc_cluster_link_l2()
1111      * clusters), the next write will reuse them anyway.  in qcow2_alloc_cluster_link_l2()
1126  * Frees the allocated clusters because the request failed and they won't
1150  * @l2_slice contains the L2 entries of all clusters involved in this
1153  * If @keep_old is true it means that the clusters were already
1154  * allocated and will be overwritten. If false then the clusters are
1352  * Returns the number of contiguous clusters that can be written to
1356  * If @new_alloc is true this counts clusters that are either
1360  * If @new_alloc is false this counts clusters that are already
1361  * allocated and can be overwritten in-place (this includes clusters
1429              * Clusters intersect but COW areas don't. And cluster itself is  in handle_dependencies()
1458              * the free/allocated clusters when we continue.  in handle_dependencies()
1465     /* Make sure that existing clusters and new allocations are only used up to  in handle_dependencies()
1473  * Checks how many already allocated clusters that don't require a new
1475  * If *host_offset is not INV_OFFSET, only physically contiguous clusters
1483  *   0:     if no allocated clusters are available at the given offset.
1488  *   1:     if allocated clusters that can be overwritten in place are
1513      * Calculate the number of clusters to look for. We stop at L2 slice  in handle_copied()
1551         /* We keep all QCOW_OFLAG_COPIED clusters */  in handle_copied()
1586  * Allocates new clusters for the given guest_offset.
1589  * contain the number of clusters that have been allocated and are contiguous
1593  * at which the new clusters must start. *nb_clusters can be 0 on return in
1595  * is INV_OFFSET, the clusters can be allocated anywhere in the image file.
1620     /* Allocate new clusters */  in do_alloc_cluster_offset()
1641  * Allocates new clusters for an area that is either still unallocated or
1643  * clusters are only allocated if the new allocation can match the specified
1651  *   0:     if no clusters could be allocated. *bytes is set to 0,
1654  *   1:     if new clusters were allocated. *bytes may be decreased if the
1678      * Calculate the number of clusters to look for. We stop at L2 slice  in handle_alloc()
1698     /* This function is only called when there were no non-COW clusters, so if  in handle_alloc()
1699      * we can't find any unallocated or COW clusters either, something is  in handle_alloc()
1759  * clusters (or subclusters) if necessary. The result can span a
1760  * combination of allocated and previously unallocated clusters.
1771  * If any clusters or subclusters were allocated then @m contains a
1775  * allocated clusters (on success) or freeing them (on failure), and
1826          * Now start gathering as many contiguous clusters as possible:  in qcow2_alloc_host_offset()
1834          *         for contiguous clusters (the situation could have changed  in qcow2_alloc_host_offset()
1861          * 2. Count contiguous COPIED clusters.  in qcow2_alloc_host_offset()
1873          * 3. If the request still hasn't completed, allocate new clusters,  in qcow2_alloc_host_offset()
1897  * This discards as many clusters of nb_clusters as possible at once (i.e.
1898  * all clusters in the same L2 slice) and returns the number of discarded
1899  * clusters.
2036  * This zeroes as many clusters of nb_clusters as possible at once (i.e.
2037  * all clusters in the same L2 slice) and returns the number of zeroed
2038  * clusters.
2119     /* For full clusters use zero_in_l2_slice() instead */  in zero_l2_subclusters()
2131         ret = -ENOTSUP; /* We cannot partially zeroize compressed clusters */  in zero_l2_subclusters()
2241  * Expands all zero clusters in a specific L1 table (or deallocates them, for
2242  * non-backed non-pre-allocated zero clusters).
2459  * For backed images, expands all zero clusters on the image. For non-backed
2460  * images, deallocates all non-pre-allocated zero clusters (and claims the
2462  * qcow2 version which doesn't yet support metadata zero clusters.
2491      * zero clusters that have already been expanded); furthermore, it is also  in qcow2_expand_zero_clusters()