[linux-2.6-block.git] / lib / list_debug.c

/*
 * Copyright 2006, Red Hat, Inc., Dave Jones
 * Released under the General Public License (GPL).
 *
 * This file contains the linked list implementations for
 * DEBUG_LIST.
 */

#include <linux/export.h>
#include <linux/list.h>
#include <linux/bug.h>
#include <linux/kernel.h>
#include <linux/rculist.h>

/*
 * Insert a new entry between two known consecutive entries.
 *
 * This is only for internal list manipulation where we know
 * the prev/next entries already!
 */

void __list_add(struct list_head *new,
			      struct list_head *prev,
			      struct list_head *next)
{
	WARN(next->prev != prev,
		"list_add corruption. next->prev should be "
		"prev (%p), but was %p. (next=%p).\n",
		prev, next->prev, next);
	WARN(prev->next != next,
		"list_add corruption. prev->next should be "
		"next (%p), but was %p. (prev=%p).\n",
		next, prev->next, prev);
	next->prev = new;
	new->next = next;
	new->prev = prev;
	prev->next = new;
}
EXPORT_SYMBOL(__list_add);

void __list_del_entry(struct list_head *entry)
{
	struct list_head *prev, *next;

	prev = entry->prev;
	next = entry->next;

	if (WARN(next == LIST_POISON1,
		"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
		entry, LIST_POISON1) ||
	    WARN(prev == LIST_POISON2,
		"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
		entry, LIST_POISON2) ||
	    WARN(prev->next != entry,
		"list_del corruption. prev->next should be %p, "
		"but was %p\n", entry, prev->next) ||
	    WARN(next->prev != entry,
		"list_del corruption. next->prev should be %p, "
		"but was %p\n", entry, next->prev))
		return;

	__list_del(prev, next);
}
EXPORT_SYMBOL(__list_del_entry);

/**
 * list_del - deletes entry from list.
 * @entry: the element to delete from the list.
 * Note: list_empty on entry does not return true after this, the entry is
 * in an undefined state.
 */
void list_del(struct list_head *entry)
{
	__list_del_entry(entry);
	entry->next = LIST_POISON1;
	entry->prev = LIST_POISON2;
}
EXPORT_SYMBOL(list_del);

/*
 * RCU variants.
 */
void __list_add_rcu(struct list_head *new,
		    struct list_head *prev, struct list_head *next)
{
	WARN(next->prev != prev,
		"list_add_rcu corruption. next->prev should be "
		"prev (%p), but was %p. (next=%p).\n",
		prev, next->prev, next);
	WARN(prev->next != next,
		"list_add_rcu corruption. prev->next should be "
		"next (%p), but was %p. (prev=%p).\n",
		next, prev->next, prev);
	new->next = next;
	new->prev = prev;
	rcu_assign_pointer(list_next_rcu(prev), new);
	next->prev = new;
}
EXPORT_SYMBOL(__list_add_rcu);
Commit	Line	Data
199a9afc DJ	1	/*
	2	* Copyright 2006, Red Hat, Inc., Dave Jones
	3	* Released under the General Public License (GPL).
	4	*
	5	* This file contains the linked list implementations for
	6	* DEBUG_LIST.
	7	*/
	8
8bc3bcc9	9	#include <linux/export.h>
199a9afc	10	#include <linux/list.h>
50af5ead	11	#include <linux/bug.h>
b116ee4d	12	#include <linux/kernel.h>
559f9bad	13	#include <linux/rculist.h>
199a9afc DJ	14
	15	/*
	16	* Insert a new entry between two known consecutive entries.
	17	*
	18	* This is only for internal list manipulation where we know
	19	* the prev/next entries already!
	20	*/
	21
	22	void __list_add(struct list_head *new,
	23	struct list_head *prev,
	24	struct list_head *next)
	25	{
924d9add DJ	26	WARN(next->prev != prev,
	27	"list_add corruption. next->prev should be "
	28	"prev (%p), but was %p. (next=%p).\n",
	29	prev, next->prev, next);
	30	WARN(prev->next != next,
	31	"list_add corruption. prev->next should be "
	32	"next (%p), but was %p. (prev=%p).\n",
	33	next, prev->next, prev);
199a9afc DJ	34	next->prev = new;
	35	new->next = next;
	36	new->prev = prev;
	37	prev->next = new;
	38	}
	39	EXPORT_SYMBOL(__list_add);
	40
3c18d4de LT	41	void __list_del_entry(struct list_head *entry)
	42	{
	43	struct list_head prev, next;
	44
	45	prev = entry->prev;
	46	next = entry->next;
	47
	48	if (WARN(next == LIST_POISON1,
	49	"list_del corruption, %p->next is LIST_POISON1 (%p)\n",
	50	entry, LIST_POISON1) \|\|
	51	WARN(prev == LIST_POISON2,
	52	"list_del corruption, %p->prev is LIST_POISON2 (%p)\n",
	53	entry, LIST_POISON2) \|\|
	54	WARN(prev->next != entry,
	55	"list_del corruption. prev->next should be %p, "
	56	"but was %p\n", entry, prev->next) \|\|
	57	WARN(next->prev != entry,
	58	"list_del corruption. next->prev should be %p, "
	59	"but was %p\n", entry, next->prev))
	60	return;
	61
	62	__list_del(prev, next);
	63	}
	64	EXPORT_SYMBOL(__list_del_entry);
	65
199a9afc DJ	66	/**
	67	* list_del - deletes entry from list.
	68	* @entry: the element to delete from the list.
	69	* Note: list_empty on entry does not return true after this, the entry is
	70	* in an undefined state.
	71	*/
	72	void list_del(struct list_head *entry)
	73	{
3c18d4de	74	__list_del_entry(entry);
199a9afc DJ	75	entry->next = LIST_POISON1;
	76	entry->prev = LIST_POISON2;
	77	}
	78	EXPORT_SYMBOL(list_del);
559f9bad DJ	79
	80	/*
	81	* RCU variants.
	82	*/
	83	void __list_add_rcu(struct list_head *new,
	84	struct list_head prev, struct list_head next)
	85	{
	86	WARN(next->prev != prev,
	87	"list_add_rcu corruption. next->prev should be "
	88	"prev (%p), but was %p. (next=%p).\n",
	89	prev, next->prev, next);
	90	WARN(prev->next != next,
	91	"list_add_rcu corruption. prev->next should be "
	92	"next (%p), but was %p. (prev=%p).\n",
	93	next, prev->next, prev);
	94	new->next = next;
	95	new->prev = prev;
	96	rcu_assign_pointer(list_next_rcu(prev), new);
	97	next->prev = new;
	98	}
	99	EXPORT_SYMBOL(__list_add_rcu);