Am 11.09.2010 16:04, schrieb Anthony Liguori:
> The use of protocols in backing_files is currently broken because of some
> checks for adjusting relative pathnames.
>
> Additionally, there's a spurious read when using an nbd protocol that can be
> quite destructive when using copy-on-read. Potentially, this can lead to
> probing an image file over top of NBD but this is completely wrong as NBD
> devices are not growable.
>
> Signed-off-by: Anthony Liguori <aligu...@us.ibm.com>
> ---
> NB: this is absolutely not ideal. A more elegant suggestion would be
> appreciated. I don't think NBD cleanly fits the model of a protocol as it
> stands today.
>
> diff --git a/block.c b/block.c
> index cd2ee31..a32d5dd 100644
> --- a/block.c
> +++ b/block.c
> @@ -344,6 +344,12 @@ static int find_image_format(const char *filename,
> BlockDriver **pdrv)
> return ret;
> }
>
> + if (strcmp(bs->drv->protocol_name, "nbd") == 0) {
> + drv = bs->drv;
> + bdrv_delete(bs);
> + goto out;
> + }
Is nbd really the only protocol that behaves like this? I don't like
hardcoding driver names in generic block layer code.
Kevin
