1 files changed, 13 insertions, 1 deletions

diff --git a/mm/vmscan.c b/mm/vmscan.c
index bc5d4f43036c..71a02e295037 100644
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -290,11 +290,23 @@ static void handle_write_error(struct address_space *mapping,
         unlock_page(page);
 }
 
+/* possible outcome of pageout() */
+typedef enum {
+        /* failed to write page out, page is locked */
+        PAGE_KEEP,
+        /* move page to the active list, page is locked */
+        PAGE_ACTIVATE,
+        /* page has been sent to the disk successfully, page is unlocked */
+        PAGE_SUCCESS,
+        /* page is clean and locked */
+        PAGE_CLEAN,
+} pageout_t;
+
 /*
  * pageout is called by shrink_page_list() for each dirty page.
  * Calls ->writepage().
  */
-pageout_t pageout(struct page *page, struct address_space *mapping)
+static pageout_t pageout(struct page *page, struct address_space *mapping)
 {
         /*
          * If the page is dirty, only perform writeback if that write