Re: [Qemu-devel] [PATCH v3 1/4] qemu-img: Convert by cluster size if target is compressed

[Stefan Hajnoczi]

On Fri, Apr 25, 2014 at 04:00:49PM +0800, Fam Zheng wrote:
> diff --git a/include/block/block.h b/include/block/block.h
> index b3230a2..8a1cb83 100644
> --- a/include/block/block.h
> +++ b/include/block/block.h
> @@ -34,6 +34,10 @@ typedef struct BlockDriverInfo {
>       * opened with BDRV_O_UNMAP flag for this to work.
>       */
>      bool can_write_zeroes_with_unmap;
> +    /*
> +     * True if the driver is writing data clusters compressed
> +     */
> +    bool is_compressed;

"is_compressed" is more general than what this flag actually
communicates:

/*
 * True if this block driver only supports compressed writes
 */
bool needs_compressed_writes;