Re: [Qemu-devel] [Qemu-block] [PATCH v3 01/11] block: Accept node-name for block-stream

[Alberto Garcia]

On Thu 07 Jul 2016 02:11:27 PM CEST, Kevin Wolf wrote:
> In order to remove the necessity to use BlockBackend names in the
> external API, we want to allow node-names everywhere. This converts
> block-stream to accept a node-name without lifting the restriction that
> we're operating at a root node.
>
> In case of an invalid device name, the command returns the GenericError
> error class now instead of DeviceNotFound, because this is what
> qmp_get_root_bs() returns.
>
> Signed-off-by: Kevin Wolf <address@hidden>
> ---
>  blockdev.c             | 32 ++++++++++++++++++++------------
>  qapi/block-core.json   |  5 +----
>  qmp-commands.hx        |  2 +-
>  tests/qemu-iotests/030 |  2 +-
>  4 files changed, 23 insertions(+), 18 deletions(-)
>
> diff --git a/blockdev.c b/blockdev.c
> index 0f8065c..01e57c9 100644
> --- a/blockdev.c
> +++ b/blockdev.c
> @@ -1172,6 +1172,23 @@ fail:
>      return dinfo;
>  }
>  
> +static BlockDriverState *qmp_get_root_bs(const char *name, Error **errp)
> +{
> +    BlockDriverState *bs;
> +
> +    bs = bdrv_lookup_bs(name, name, errp);
> +    if (bs == NULL) {
> +        return NULL;
> +    }
> +
> +    if (!bdrv_has_blk(bs)) {
> +        error_setg(errp, "Need a root block node");
> +        return NULL;
> +    }

Since b6d2e59995f when you create a block job a new BlockBackend is
created on top of the BDS. What happens with this check if we allow
creating jobs in a non-root BDS? 

Berto