LU-8900 snapshot: user interface for write barrier on MDT

[fs/lustre-release.git] / libcfs / include / libcfs / util / list.h

diff --git a/libcfs/include/libcfs/util/list.h b/libcfs/include/libcfs/util/list.h
index 2372f5b..ef69efe 100644 (file)
--- a/libcfs/include/libcfs/util/list.h
+++ b/libcfs/include/libcfs/util/list.h
@@ -483,4 +483,17 @@ static inline void hlist_add_after(struct hlist_node *n,
             &pos->member != (head);                                         \
             pos = n, n = list_entry(n->member.next, typeof(*n), member))
 
+/**
+ * Iterate backwards over a list of given type safely against removal of entry
+ * \param pos        the type * to use as a loop counter.
+ * \param n          another type * to use as temporary storage
+ * \param head       the head for your list.
+ * \param member     the name of the list_struct within the struct.
+ */
+#define list_for_each_entry_safe_reverse(pos, n, head, member)         \
+       for (pos = list_entry((head)->prev, typeof(*pos), member),      \
+               n = list_entry(pos->member.prev, typeof(*pos), member); \
+            &pos->member != (head);                                    \
+            pos = n, n = list_entry(n->member.prev, typeof(*n), member))
+
 #endif /* __LIBCFS_UTIL_LIST_H__ */