static int get_whole_cluster(BlockDriverState *bs, VmdkExtent *extent, uint64_t cluster_offset, uint64_t offset, bool allocate) { /* 128 sectors * 512 bytes each = grain size 64KB */ uint8_t whole_grain[extent->cluster_sectors * 512]; /* we will be here if it's first write on non-exist grain(cluster). * try to read from parent image, if exist */ if (bs->backing_hd) { int ret; if (!vmdk_is_cid_valid(bs)) return -1; /* floor offset to cluster */ offset -= offset % (extent->cluster_sectors * 512); ret = bdrv_read(bs->backing_hd, offset >> 9, whole_grain, extent->cluster_sectors); if (ret < 0) { return -1; } /* Write grain only into the active image */ ret = bdrv_write(extent->file, cluster_offset, whole_grain, extent->cluster_sectors); if (ret < 0) { return -1; } } return 0; }