This commit was manufactured by cvs2svn to create branch 'vserver'.

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

diff --git a/lib/list_debug.c b/lib/list_debug.c
new file mode 100644 (file)
index 0000000..1aae85c
--- /dev/null
+++ b/lib/list_debug.c
@@ -0,0 +1,77 @@
+/*
+ * 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/module.h>
+#include <linux/list.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)
+{
+       if (unlikely(next->prev != prev)) {
+               printk(KERN_ERR "list_add corruption. next->prev should be %p, but was %p\n",
+                       prev, next->prev);
+               BUG();
+       }
+       if (unlikely(prev->next != next)) {
+               printk(KERN_ERR "list_add corruption. prev->next should be %p, but was %p\n",
+                       next, prev->next);
+               BUG();
+       }
+       next->prev = new;
+       new->next = next;
+       new->prev = prev;
+       prev->next = new;
+}
+EXPORT_SYMBOL(__list_add);
+
+/**
+ * list_add - add a new entry
+ * @new: new entry to be added
+ * @head: list head to add it after
+ *
+ * Insert a new entry after the specified head.
+ * This is good for implementing stacks.
+ */
+void list_add(struct list_head *new, struct list_head *head)
+{
+       __list_add(new, head, head->next);
+}
+EXPORT_SYMBOL(list_add);
+
+/**
+ * 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)
+{
+       if (unlikely(entry->prev->next != entry)) {
+               printk(KERN_ERR "list_del corruption. prev->next should be %p, but was %p\n",
+                       entry, entry->prev->next);
+               BUG();
+       }
+       if (unlikely(entry->next->prev != entry)) {
+               printk(KERN_ERR "list_del corruption. next->prev should be %p, but was %p\n",
+                       entry, entry->next->prev);
+               BUG();
+       }
+       __list_del(entry->prev, entry->next);
+       entry->next = LIST_POISON1;
+       entry->prev = LIST_POISON2;
+}
+EXPORT_SYMBOL(list_del);
+