+/**
+ * page_is_file_cache - should the page be on a file LRU or anon LRU?
+ * @page: the page to test
+ *
+ * Returns LRU_FILE if @page is page cache page backed by a regular filesystem,
+ * or 0 if @page is anonymous, tmpfs or otherwise ram or swap backed.
+ * Used by functions that manipulate the LRU lists, to sort a page
+ * onto the right LRU list.
+ *
+ * We would like to get this info without a page flag, but the state
+ * needs to survive until the page is last deleted from the LRU, which
+ * could be as far down as __page_cache_release.
+ */
+static inline int page_is_file_cache(struct page *page)