03.03.2020 16:34, Denis Plotnikov wrote:
The patch adds some preparation parts for incompatible compression type feature to qcow2 allowing the use different compression methods for image clusters (de)compressing.It is implied that the compression type is set on the image creation and can be changed only later by image conversion, thus compression type defines the only compression algorithm used for the image, and thus, for all image clusters. The goal of the feature is to add support of other compression methods to qcow2. For example, ZSTD which is more effective on compression than ZLIB. The default compression is ZLIB. Images created with ZLIB compression type are backward compatible with older qemu versions. Adding of the compression type breaks a number of tests because now the compression type is reported on image creation and there are some changes in the qcow2 header in size and offsets. The tests are fixed in the following ways: * filter out compression_type for all the tests * fix header size, feature table size and backing file offset affected tests: 031, 036, 061, 080 header_size +=8: 1 byte compression type 7 bytes padding feature_table += 48: incompatible feture compression type backing_file_offset += 56 (8 + 48 -> header_change + fature_table_change) * add "compression type" for test output matching when it isn't filtered affected tests: 049, 060, 061, 065, 144, 182, 242, 255 Signed-off-by: Denis Plotnikov<[email protected]>
Reviewed-by: Vladimir Sementsov-Ogievskiy <[email protected]> -- Best regards, Vladimir
