[PATCH v2 07/17] libvirt-storage: Document volume upload/download stream format

[Peter Krempa]

On Tue, Jul 07, 2020 at 21:46:25 +0200, Michal Privoznik wrote:
> For libvirt, the volume is just a binary blob and it doesn't
> interpret data on volume upload/download. But as it turns out,
> this unspoken assumption is not clear to our users. Document it
> explicitly.
> 
> Suggested in: https://bugzilla.redhat.com/show_bug.cgi?id=1851023#c17
> 
> Signed-off-by: Michal Privoznik <mprivozn at redhat.com>
> ---
>  src/libvirt-storage.c | 8 ++++++--
>  1 file changed, 6 insertions(+), 2 deletions(-)
> 
> diff --git a/src/libvirt-storage.c b/src/libvirt-storage.c
> index a45c8b98c1..8738f6dd14 100644
> --- a/src/libvirt-storage.c
> +++ b/src/libvirt-storage.c
> @@ -1590,7 +1590,9 @@ virStorageVolCreateXMLFrom(virStoragePoolPtr pool,
>   *
>   * Download the content of the volume as a stream. If @length
>   * is zero, then the remaining contents of the volume after
> - * @offset will be downloaded.
> + * @offset will be downloaded. Please note, that the data is
> + * not interpreted and therefore data received by stream
> + * client are in the very same format the volume is in.

I don't think this wording clarifies it that much as it's not obvious
what's meant by 'interpreted'.

How about:

Please note that the stream transports the volume itself as is, so the
downloaded data may not correspond to guest OS visible state in cases
when a complex storage format such as qcow2 or vmdk is used.