Re: [Qemu-devel] [PATCH v2 2/3] qcow2.py: Add required padding for header extensions

[Max Reitz <mreitz@redhat.com>]

On 2014-11-25 at 18:12, Kevin Wolf wrote:
> The qcow2 specification requires that the header extension data be
> padded to round up the extension size to the next multiple of 8 bytes.
>
> Signed-off-by: Kevin Wolf <kwolf@redhat.com>
> ---
>   tests/qemu-iotests/qcow2.py | 4 ++++
>   1 file changed, 4 insertions(+)
>
> diff --git a/tests/qemu-iotests/qcow2.py b/tests/qemu-iotests/qcow2.py
> index 2058596..9cc4cf7 100755
> --- a/tests/qemu-iotests/qcow2.py
> +++ b/tests/qemu-iotests/qcow2.py
> @@ -7,6 +7,10 @@ import string
>   class QcowHeaderExtension:
>   
>       def __init__(self, magic, length, data):
> +        if length % 8 != 0:
> +            padding = 8 - (length % 8)
> +            data += "\0" * padding

So it does work that way, great. *g*

> +
>           self.magic  = magic
>           self.length = length
>           self.data   = data

Reviewed-by: Max Reitz <mreitz@redhat.com>