diff --git a/fs/nfs/internal.h b/fs/nfs/internal.h
index 6610f2b..ad2b40d 100644
--- a/fs/nfs/internal.h
+++ b/fs/nfs/internal.h
@@ -231,3 +231,15 @@
 	}
 	return 0;
 }
+
+/*
+ * Determine the number of pages in an array of length 'len' and
+ * with a base offset of 'base'
+ */
+static inline
+unsigned int nfs_page_array_len(unsigned int base, size_t len)
+{
+	return ((unsigned long)len + (unsigned long)base +
+		PAGE_SIZE - 1) >> PAGE_SHIFT;
+}
+