[PATCH] invalidate: remove_mapping() fix

[mirror_ubuntu-zesty-kernel.git] / mm / vmscan.c

diff --git a/mm/vmscan.c b/mm/vmscan.c
index eca70310adb26239e94c5435eaf2abf0271c89fa..af73c14f9d88e862942fe78ba9ac64b2013a3112 100644 (file)
--- a/mm/vmscan.c
+++ b/mm/vmscan.c
@@ -378,6 +378,12 @@ static pageout_t pageout(struct page *page, struct address_space *mapping)
        return PAGE_CLEAN;
 }
 
+/*
+ * Attempt to detach a locked page from its ->mapping.  If it is dirty or if
+ * someone else has a ref on the page, abort and return 0.  If it was
+ * successfully detached, return 1.  Assumes the caller has a single ref on
+ * this page.
+ */
 int remove_mapping(struct address_space *mapping, struct page *page)
 {
        BUG_ON(!PageLocked(page));