+/**
+ * list_next - get the next entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the last entry in the list, returns NULL.
+ *
+ * Example:
+ * struct child *second;
+ * second = list_next(&parent->children, first, list);
+ * if (!second)
+ * printf("No second child!\n");
+ */
+#define list_next(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h, \
+ __FILE__ ":" stringify(__LINE__)), \
+ (i)->member.next, \
+ list_off_var_((i), member)))
+
+/**
+ * list_prev - get the previous entry in a list
+ * @h: the list_head
+ * @i: a pointer to an entry in the list.
+ * @member: the list_node member of the structure
+ *
+ * If @i was the first entry in the list, returns NULL.
+ *
+ * Example:
+ * first = list_prev(&parent->children, second, list);
+ * if (!first)
+ * printf("Can't go back to first child?!\n");
+ */
+#define list_prev(h, i, member) \
+ ((list_typeof(i))list_entry_or_null(list_debug(h, \
+ __FILE__ ":" stringify(__LINE__)), \
+ (i)->member.prev, \
+ list_off_var_((i), member)))
+
+/**
+ * list_append_list - empty one list onto the end of another.
+ * @to: the list to append into
+ * @from: the list to empty.
+ *
+ * This takes the entire contents of @from and moves it to the end of
+ * @to. After this @from will be empty.
+ *
+ * Example:
+ * struct list_head adopter;
+ *
+ * list_append_list(&adopter, &parent->children);
+ * assert(list_empty(&parent->children));
+ * parent->num_children = 0;
+ */
+#define list_append_list(t, f) list_append_list_(t, f, \
+ __FILE__ ":" stringify(__LINE__))
+static inline void list_append_list_(struct list_head *to,
+ struct list_head *from,
+ const char *abortstr)
+{
+ struct list_node *from_tail = list_debug(from, abortstr)->n.prev;
+ struct list_node *to_tail = list_debug(to, abortstr)->n.prev;
+
+ /* Sew in head and entire list. */
+ to->n.prev = from_tail;
+ from_tail->next = &to->n;
+ to_tail->next = &from->n;
+ from->n.prev = to_tail;
+
+ /* Now remove head. */
+ list_del(&from->n);
+ list_head_init(from);
+}
+
+/**
+ * list_prepend_list - empty one list into the start of another.
+ * @to: the list to prepend into
+ * @from: the list to empty.
+ *
+ * This takes the entire contents of @from and moves it to the start
+ * of @to. After this @from will be empty.
+ *
+ * Example:
+ * list_prepend_list(&adopter, &parent->children);
+ * assert(list_empty(&parent->children));
+ * parent->num_children = 0;
+ */
+#define list_prepend_list(t, f) list_prepend_list_(t, f, LIST_LOC)
+static inline void list_prepend_list_(struct list_head *to,
+ struct list_head *from,
+ const char *abortstr)
+{
+ struct list_node *from_tail = list_debug(from, abortstr)->n.prev;
+ struct list_node *to_head = list_debug(to, abortstr)->n.next;
+
+ /* Sew in head and entire list. */
+ to->n.next = &from->n;
+ from->n.prev = &to->n;
+ to_head->prev = from_tail;
+ from_tail->next = to_head;
+
+ /* Now remove head. */
+ list_del(&from->n);
+ list_head_init(from);
+}
+
+/* internal macros, do not use directly */
+#define list_for_each_off_dir_(h, i, off, dir) \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \
+ (off)); \
+ list_node_from_off_((void *)i, (off)) != &(h)->n; \
+ i = list_node_to_off_(list_node_from_off_((void *)i, (off))->dir, \
+ (off)))
+
+#define list_for_each_safe_off_dir_(h, i, nxt, off, dir) \
+ for (i = list_node_to_off_(list_debug(h, LIST_LOC)->n.dir, \
+ (off)), \
+ nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \
+ (off)); \
+ list_node_from_off_(i, (off)) != &(h)->n; \
+ i = nxt, \
+ nxt = list_node_to_off_(list_node_from_off_(i, (off))->dir, \
+ (off)))
+