mm, rmap: fix false positive VM_BUG() in page_add_file_rmap()

[platform/kernel/linux-rpi.git] / mm / rmap.c

diff --git a/mm/rmap.c b/mm/rmap.c
index 709bc83..d4f5606 100644 (file)
--- a/mm/rmap.c
+++ b/mm/rmap.c
@@ -1284,8 +1284,9 @@ void page_add_file_rmap(struct page *page, bool compound)
                VM_BUG_ON_PAGE(!PageSwapBacked(page), page);
                __inc_node_page_state(page, NR_SHMEM_PMDMAPPED);
        } else {
-               if (PageTransCompound(page)) {
-                       VM_BUG_ON_PAGE(!PageLocked(page), page);
+               if (PageTransCompound(page) && page_mapping(page)) {
+                       VM_WARN_ON_ONCE(!PageLocked(page));
+
                        SetPageDoubleMap(compound_head(page));
                        if (PageMlocked(page))
                                clear_page_mlock(compound_head(page));