Previously, autofs would not always read file maps. If a map had been loaded into cache, autofs would rely on checks to determine whether the map was up to date before reading the map. Because file maps require a linear search through the file, large maps consume significant resources to process. Now, autofs automatically loads file-based maps when it starts, and uses the map file mtime parameter to detemine whether the cache needs to be refresed. This avoids the processing overhead of checking a map before deciding whether to load it.