On Fri, 27 Mar 2015 13:36:11 +0800
Lin Ma <l...@suse.com> wrote:
> If backends implement the can_be_deleted and it returns false,
> Then the qmp_object_del won't delete the given backends.
>
> Signed-off-by: Lin Ma <l...@suse.com>
> ---
> include/qom/object_interfaces.h | 14 ++++++++++++++
> qmp.c | 5 +++++
> qom/object_interfaces.c | 15 +++++++++++++++
> 3 files changed, 34 insertions(+)
>
> diff --git a/include/qom/object_interfaces.h b/include/qom/object_interfaces.h
> index b792283..012b653 100644
> --- a/include/qom/object_interfaces.h
> +++ b/include/qom/object_interfaces.h
> @@ -25,6 +25,8 @@ typedef struct UserCreatable {
> * UserCreatableClass:
> * @parent_class: the base class
> * @complete: callback to be called after @obj's properties are set.
> + * @can_be_deleted: callback to be called before an object is removed
> + * to check if @obj can be removed safely.
> *
> * Interface is designed to work with -object/object-add/object_add
> * commands.
> @@ -47,6 +49,7 @@ typedef struct UserCreatableClass {
>
> /* <public> */
> void (*complete)(UserCreatable *uc, Error **errp);
> + bool (*can_be_deleted)(UserCreatable *uc, Error **errp);
> } UserCreatableClass;
>
> /**
> @@ -59,4 +62,15 @@ typedef struct UserCreatableClass {
> * nothing.
> */
> void user_creatable_complete(Object *obj, Error **errp);
> +
> +/**
> + * user_creatable_can_be_deleted:
> + * @obj: the object whose can_be_deleted() method is called if defined
> + * @errp: if an error occurs, a pointer to an area to store the error
> + *
> + * Wrapper to call can_be_deleted() method if one of types it's inherited
> + * from implements USER_CREATABLE interface, otherwise the call does
> + * nothing.
> + */
> +bool user_creatable_can_be_deleted(Object *obj, Error **errp);
> #endif
> diff --git a/qmp.c b/qmp.c
> index c479e77..dc61da1 100644
> --- a/qmp.c
> +++ b/qmp.c
> @@ -711,6 +711,11 @@ void qmp_object_del(const char *id, Error **errp)
> error_setg(errp, "object id not found");
> return;
> }
> +
> + if (!user_creatable_can_be_deleted(obj, errp)) {
> + error_setg(errp, "%s is in used, can not be deleted", id);
^^^ is in use || is used
> + return;
> + }
> object_unparent(obj);
> }
>
> diff --git a/qom/object_interfaces.c b/qom/object_interfaces.c
> index 6360818..25ae6ca 100644
> --- a/qom/object_interfaces.c
> +++ b/qom/object_interfaces.c
> @@ -18,6 +18,21 @@ void user_creatable_complete(Object *obj, Error **errp)
> }
> }
>
> +bool user_creatable_can_be_deleted(Object *obj, Error **errp)
> +{
> +
> + UserCreatableClass *ucc;
> + UserCreatable *uc =
> + (UserCreatable *)object_dynamic_cast(obj, TYPE_USER_CREATABLE);
direc cast is wron, pls use type specific caster with QOM objects
in this case you can even drop dynamic cast since /objects holds
only TYPE_USER_CREATABLE objects and just do
UserCreatable *uc = USER_CREATABLE(obj)
you don't check for null pointer anyway
> +
> + ucc = USER_CREATABLE_GET_CLASS(uc);
> + if (ucc->can_be_deleted) {
> + return ucc->can_be_deleted(uc, errp);
> + } else {
> + return true;
> + }
> +}
> +
> static void register_types(void)
> {
> static const TypeInfo uc_interface_info = {
