linux内核链表的定义（定义了双向链表，不含数据域）
定义在 /linux-source-3.13.0/include/linux/types.h 头文件中．
1 struct list_head { 2 struct list_head *next, *prev; 3 };
我们可以利用这个数据结构定义含有数据域的链表，如：
1 struct my_list 2 { 3 void * mydata; //void * 可以指向任何类型的数据 4 struct list_head list; //隐藏了链表指针 5 }
链表的声明和初始化宏（list.h）
定义在 /linux-source-3.13.0/include/linux/list.h 中．
1 #define LIST_HEAD_INIT(name) { &(name), &(name) }
初始化一个名为name的双向链表的头节点．（name.pre = &name , name.next = &name）
1 #define LIST_HEAD(name) 2 struct list_head name = LIST_HEAD_INIT(name)
通过调用LIST_HEAD，来声明和初始化一个自己的链表头，产生一个空链表．如：LIST_HEAD（mylist_head）
在链表添加一个节点
定义在 /linux-source-3.13.0/include/linux/list.h 中
具体实现：
1 /* 2 * Insert a new entry between two known consecutive entries. 3 * 4 * This is only for internal list manipulation where we know 5 * the prev/next entries already! 6 */ 7 #ifndef CONFIG_DEBUG_LIST 8 static inline void __list_add(struct list_head *new, 9 struct list_head *prev, 10 struct list_head *next) 11 { 12 next->prev = new; 13 new->next = next; 14 new->prev = prev; 15 prev->next = new; 16 } 17 #else 18 extern void __list_add(struct list_head *new, 19 struct list_head *prev, 20 struct list_head *next); 21 #endif 22 23 /** 24 * list_add - add a new entry 25 * @new: new entry to be added 26 * @head: list head to add it after 27 * 28 * Insert a new entry after the specified head. 29 * This is good for implementing stacks. 30 */ 31 static inline void list_add(struct list_head *new, struct list_head *head) //在head节点后插入new节点，循环链表没有首尾，head可以是任意节点 32 { 33 __list_add(new, head, head->next); 34 } 35 36 /** 37 * list_add_tail - add a new entry 38 * @new: new entry to be added 39 * @head: list head to add it before 40 * 41 * Insert a new entry before the specified head. 42 * This is useful for implementing queues. 43 */ 44 static inline void list_add_tail(struct list_head *new, struct list_head *head) //在head节点前插入new节点 45 { 46 __list_add(new, head->prev, head); 47 }
遍历链表
定义在 /linux-source-3.13.0/include/linux/list.h 中
1 /** 2 * list_for_each - iterate over a list 3 * @pos: the &struct list_head to use as a loop cursor. 4 * @head: the head for your list. 5 */ 6 #define list_for_each(pos, head) 7 for (pos = (head)->next; pos != (head); pos = pos->next)
它实际上是一个for循环，利用传入的pos作为循环变量，从表头开始逐顶向后（next方向）移动pos，直至回到head.
1 /** 2 * list_entry - get the struct for this entry 3 * @ptr: the &struct list_head pointer. 4 * @type: the type of the struct this is embedded in. 5 * @member: the name of the list_struct within the struct. 6 */ 7 #define list_entry(ptr, type, member) 8 container_of(ptr, type, member)
list_entry宏：从结构体（type）某成员变量（menber）指针（prt）来求出该结构体（type）的首指针．