On 04.07.19 15:09, Denis Plotnikov wrote:
> The patch allow to process image compression type defined
> in the image header and choose an appropriate method for
> image clusters (de)compression.
> 
> Signed-off-by: Denis Plotnikov <dplotnikov@virtuozzo.com>
> ---
>  block/qcow2.c | 93 ++++++++++++++++++++++++++++++++++++++++-----------
>  1 file changed, 73 insertions(+), 20 deletions(-)
> 
> diff --git a/block/qcow2.c b/block/qcow2.c
> index 8fa932a349..a107f76e98 100644
> --- a/block/qcow2.c
> +++ b/block/qcow2.c

[...]

> @@ -4153,20 +4156,67 @@ qcow2_co_do_compress(BlockDriverState *bs, void *dest, size_t dest_size,
>      return arg.ret;
>  }
>  
> +/*
> + * qcow2_co_compress()
> + *
> + * Compress @src_size bytes of data using the compression
> + * method defined by the image compression type
> + *
> + * @dest - destination buffer, @dest_size bytes
> + * @src - source buffer, @src_size bytes
> + *
> + * Returns: 0 on success

Actually, it returns the number of compressed bytes.

Max

> + *          a negative error code on fail
> + */