nffs_list.h

/*
 * nffs_list.h
 *
 *  Created on: 2021/5/10
 *      Author: ueyudiud
 */

#ifndef NFFS_LIST_H_
#define NFFS_LIST_H_


/*
 * This is a simple doubly linked list implementation that matches the
 * way the Linux kernel doubly linked list implementation works.
 */

struct list_head {
	struct list_head *next; /* next in chain */
	struct list_head *prev; /* previous in chain */
};


/* Initialise a static list */
#define LIST_HEAD(name) \
struct list_head name = { &(name), &(name)}



/* Initialise a list head to an empty list */
#define INIT_LIST_HEAD(p) \
do { \
	(p)->next = (p);\
	(p)->prev = (p); \
} while (0)


/* Add an element to a list */
static inline void list_add(struct list_head *new_entry,
							struct list_head *list)
{
	struct list_head *list_next = list->next;

	list->next = new_entry;
	new_entry->prev = list;
	new_entry->next = list_next;
	list_next->prev = new_entry;

}

static inline void list_add_tail(struct list_head *new_entry,
								 struct list_head *list)
{
	struct list_head *list_prev = list->prev;

	list->prev = new_entry;
	new_entry->next = list;
	new_entry->prev = list_prev;
	list_prev->next = new_entry;

}


/* Take an element out of its current list, with or without
 * reinitialising the links.of the entry*/
static inline void list_del(struct list_head *entry)
{
	struct list_head *list_next = entry->next;
	struct list_head *list_prev = entry->prev;

	list_next->prev = list_prev;