mm/hwpoison: fix refcount of THP head page in no-injection case

[deliverable/linux.git] / mm / migrate.c

diff --git a/mm/migrate.c b/mm/migrate.c
index eb4267107d1fee9fa2a55e4076c014500e3b1edb..5c08cab5419e771d4b2d04762ae3d876cf8080eb 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -1226,7 +1226,9 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                if (!vma || pp->addr < vma->vm_start || !vma_migratable(vma))
                        goto set_status;
 
-               page = follow_page(vma, pp->addr, FOLL_GET|FOLL_SPLIT);
+               /* FOLL_DUMP to ignore special (like zero) pages */
+               page = follow_page(vma, pp->addr,
+                               FOLL_GET | FOLL_SPLIT | FOLL_DUMP);
 
                err = PTR_ERR(page);
                if (IS_ERR(page))
@@ -1236,10 +1238,6 @@ static int do_move_page_to_node_array(struct mm_struct *mm,
                if (!page)
                        goto set_status;
 
-               /* Use PageReserved to check for zero page */
-               if (PageReserved(page))
-                       goto put_and_set;
-
                pp->page = page;
                err = page_to_nid(page);
 
@@ -1396,18 +1394,14 @@ static void do_pages_stat_array(struct mm_struct *mm, unsigned long nr_pages,
                if (!vma || addr < vma->vm_start)
                        goto set_status;
 
-               page = follow_page(vma, addr, 0);
+               /* FOLL_DUMP to ignore special (like zero) pages */
+               page = follow_page(vma, addr, FOLL_DUMP);
 
                err = PTR_ERR(page);
                if (IS_ERR(page))
                        goto set_status;
 
-               err = -ENOENT;
-               /* Use PageReserved to check for zero page */
-               if (!page || PageReserved(page))
-                       goto set_status;
-
-               err = page_to_nid(page);
+               err = page ? page_to_nid(page) : -ENOENT;
 set_status:
                *status = err;