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authorSteven Whitehouse <swhiteho@redhat.com>2006-10-02 08:45:08 -0400
committerSteven Whitehouse <swhiteho@redhat.com>2006-10-02 08:45:08 -0400
commit59458f40e25915a355d8b1d701425fe9f4f9ea23 (patch)
treef1c9a2934df686e36d75f759ab7313b6f0e0e5f9 /lib/list_debug.c
parent825f9075d74028d11d7f5932f04e1b5db3022b51 (diff)
parentd834c16516d1ebec4766fc58c059bf01311e6045 (diff)
Merge branch 'master' into gfs2
Diffstat (limited to 'lib/list_debug.c')
-rw-r--r--lib/list_debug.c76
1 files changed, 76 insertions, 0 deletions
diff --git a/lib/list_debug.c b/lib/list_debug.c
new file mode 100644
index 00000000000..7ba9d823d38
--- /dev/null
+++ b/lib/list_debug.c
@@ -0,0 +1,76 @@
+/*
+ * 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);