#include<linux/module.h>
#include<linux/slab.h>


static struct list_node
{
	int data;
	struct list_node *next;
}*list;


static struct kmem_cache *list_cache;

static struct list_node *create_list(int data)
{
	struct list_node *front = (struct list_node *)kmem_cache_alloc(list_cache,GFP_KERNEL);

	if(front!=NULL)
	{
		front->data = data;
		front->next = front;
	}
	return front;
}

static void add_back(struct list_node *list,int number)
{
	if(list)
	{
		struct list_node *first = list;

		struct list_node *new_element = (struct list_node *)kmem_cache_alloc(list_cache,GFP_KERNEL);
		do
		{
			list = list->next;
		} while(list->next != first);
		list->next = new_element;
		new_element->next = first;
		new_element->data = number;
	}
}

static int __init list_init(void)
{
	int i;
	list_cache = kmem_cache_create("cycle list",sizeof(struct list_node),0,SLAB_HWCACHE_ALIGN|SLAB_POISON|SLAB_RED_ZONE,0);

	if(IS_ERR(list_cache))
	{
		pr_alert("Error creating cache: %ld\n",PTR_ERR(list_cache));
		return -ENOMEM;
	}
	list = create_list(100);
	for(i=101;i<=110;i++)
		add_back(list,i);
	printk(KERN_ALERT"wypelnilem liste od 100 do 110\n");
	return 0;
}

static void print_list(struct list_node *list)
{

	struct list_node *start = list;

	if(list!=NULL)
	{       printk(KERN_ALERT"LIST:\n");
		do
		{
			printk(KERN_ALERT"%d\n",list->data);
			list=list->next;
		}while(list!=start);
	}
}

static void remove_list(struct list_node **list)
{
	if(*list)
	{
		struct list_node *tmp;
		struct list_node *start =*list;

		do
		{
			tmp=(*list)->next;
			kmem_cache_free(list_cache,*list);
			*list=tmp;
		}while(*list!=start);
		*list=NULL;
	}
}

static void __exit list_exit(void)
{
	print_list(list);
	remove_list(&list);
	kmem_cache_destroy(list_cache);
}

module_init(list_init);
module_exit(list_exit);

MODULE_LICENSE("GPL");
MODULE_AUTHOR("ja");