788 struct tomoyo_io_buffer {  struct
789 	void (*read) (struct tomoyo_io_buffer *);  argument
790 	int (*write) (struct tomoyo_io_buffer *);  argument
791 	unsigned int (*poll) (struct file *file, poll_table *wait);
793 	struct mutex io_sem;
794 	char __user *read_user_buf;
795 	size_t read_user_buf_avail;
796 	struct {
834 	/* Users counter protected by tomoyo_io_buffer_list_lock. */  argument
835 	u8 users;
837 	struct list_head list;