The throttle driver is not a protocol so it should implement bdrv_open
instead of bdrv_file_open and not provide a protocol_name.

Attempts to invoke this driver using protocol syntax
(i.e. throttle:<filename:options:...>) will now fail gracefully:

  $ qemu-img info throttle:foo
  qemu-img: Could not open 'throttle:foo': Unknown protocol 'throttle'

Signed-off-by: Fabiano Rosas <farosas@linux.vnet.ibm.com>
---
 block/throttle.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

diff --git a/block/throttle.c b/block/throttle.c
index 5f4d43d0fc..95ed06acd8 100644
--- a/block/throttle.c
+++ b/block/throttle.c
@@ -215,10 +215,9 @@ static void coroutine_fn throttle_co_drain_end(BlockDriverState *bs)
 
 static BlockDriver bdrv_throttle = {
     .format_name                        =   "throttle",
-    .protocol_name                      =   "throttle",
     .instance_size                      =   sizeof(ThrottleGroupMember),
 
-    .bdrv_file_open                     =   throttle_open,
+    .bdrv_open                          =   throttle_open,
     .bdrv_close                         =   throttle_close,
     .bdrv_co_flush                      =   throttle_co_flush,
 
-- 
2.13.6

On 2018-03-09 19:21, Fabiano Rosas wrote:
> The throttle driver is not a protocol so it should implement bdrv_open
> instead of bdrv_file_open and not provide a protocol_name.
> 
> Attempts to invoke this driver using protocol syntax
> (i.e. throttle:<filename:options:...>) will now fail gracefully:
> 
>   $ qemu-img info throttle:foo
>   qemu-img: Could not open 'throttle:foo': Unknown protocol 'throttle'
> 
> Signed-off-by: Fabiano Rosas <farosas@linux.vnet.ibm.com>
> ---
>  block/throttle.c | 3 +--
>  1 file changed, 1 insertion(+), 2 deletions(-)

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