#ifndef __LINUX_RCU_TYPES_H#define __LINUX_RCU_TYPES_H#ifdef __KERNEL__/** * struct rcu_head - callback structure for use with RCU * @next: next update requests in a list * @func: actual update function to call after the grace period. */struct rcu_head {struct rcu_head *next;void(*func)(struct rcu_head *head);};#endif#endif