On Wed, 2019-07-24 at 19:12 +0200, Max Reitz wrote:
> Static VDI images cannot guarantee to be zero-initialized. If the image
> has been statically allocated, forward the call to the underlying
> storage node.
>
> Reported-by: Stefano Garzarella
> Signed-off-by: Max Reitz
> Reviewed-by: Stefan Weil
> Acked-by: Stefano Garzarella
> Tested-by: Stefano Garzarella
> ---
> block/vdi.c | 13 -
> 1 file changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/block/vdi.c b/block/vdi.c
> index b9845a4cbd..0caa3f281d 100644
> --- a/block/vdi.c
> +++ b/block/vdi.c
> @@ -988,6 +988,17 @@ static void vdi_close(BlockDriverState *bs)
> error_free(s->migration_blocker);
> }
>
> +static int vdi_has_zero_init(BlockDriverState *bs)
> +{
> +BDRVVdiState *s = bs->opaque;
> +
> +if (s->header.image_type == VDI_TYPE_STATIC) {
> +return bdrv_has_zero_init(bs->file->bs);
> +} else {
> +return 1;
> +}
> +}
> +
> static QemuOptsList vdi_create_opts = {
> .name = "vdi-create-opts",
> .head = QTAILQ_HEAD_INITIALIZER(vdi_create_opts.head),
> @@ -1028,7 +1039,7 @@ static BlockDriver bdrv_vdi = {
> .bdrv_child_perm = bdrv_format_default_perms,
> .bdrv_co_create = vdi_co_create,
> .bdrv_co_create_opts = vdi_co_create_opts,
> -.bdrv_has_zero_init = bdrv_has_zero_init_1,
> +.bdrv_has_zero_init = vdi_has_zero_init,
> .bdrv_co_block_status = vdi_co_block_status,
> .bdrv_make_empty = vdi_make_empty,
>
I am not familiar with VDI format to be honest, but knowing that dynamic format
allows for growing
and static are preallocated this makes sense.
I see that the code when it allocates a new block at the end of the file,
actually zeroes it out, so most
likely this is right.
Reviewed-by: Maxim Levitsky
Best regards,
Maxim Levitsky
