7.15 Linux内核的面向对象思想：封装（上）

字符设备

./fs/char_dev.c 用到了
include/linux/cdev.h

struct cdev {
        struct kobject kobj;
        struct module *owner;
        const struct file_operations *ops;
        struct list_head list;
        dev_t dev;
        unsigned int count;
};

设备管理模型

kobject

struct kobject {
const char  *name;
struct list_head  entry;		//链表 如将tty0 - ttyn 串起来
struct kobject  *parent;		//父目录
struct kset  *kset;				//子目录名 如tty
struct kobj_type  *ktype;
struct kernfs_node *sd;
struct kref  kref;
unsigned int state_initialized:1;
unsigned int state_in_sysfs:1;
unsigned int state_add_uevent_sent:1;		//插拔相关
unsigned int state_remove_uevent_sent:1;
unsigned int uevent_suppress:1;
};

kobj_type

struct kobj_type {
void (*release)(struct kobject *kobj);
const struct sysfs_ops *sysfs_ops;	//与系统的交互
struct attribute **default_attrs;
const struct kobj_ns_type_operations *(*child_ns_type)(struct kobject *kobj);
const void *(*namespace)(struct kobject *kobj);
};

kref

struct kref {
atomic_t refcount;
};

kset
相同类型的kobject的集合

struct kset {
struct list_head list;
spinlock_t list_lock;
struct kobject kobj;
struct kset_uevent_ops *uevent_ops;
};