void kref_init(struct kref *kref);
void kref_get(struct kref *kref);
int kref_put(struct kref *kref, void (*release) (struct kref *kref));
void kref_init(struct kref *kref);
void kref_get(struct kref *kref);
int kref_put(struct kref *kref, void (*release) (struct kref *kref));