On 06.09.18 11:37, Alberto Garcia wrote:
> 'discard' is one of the basic BlockdevOptions available for all
> drivers, but it's not handled by bdrv_reopen_prepare() so any attempt
> to change it results in an error:
> 
>    (qemu) qemu-io virtio0 "reopen -o discard=on"
>    Cannot change the option 'discard'
> 
> Since there's no reason why we shouldn't allow changing it and the
> implementation is simple let's just do it.
> 
> Signed-off-by: Alberto Garcia <berto@igalia.com>
> ---
>  block.c | 11 +++++++++++
>  1 file changed, 11 insertions(+)

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