mm/memory-failure: check the mapcount of the precise page

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

diff --git a/mm/migrate.c b/mm/migrate.c
index 06086dc..03bc206 100644 (file)
--- a/mm/migrate.c
+++ b/mm/migrate.c
@@ -405,6 +405,7 @@ int folio_migrate_mapping(struct address_space *mapping,
        int dirty;
        int expected_count = folio_expected_refs(mapping, folio) + extra_count;
        long nr = folio_nr_pages(folio);
+       long entries, i;
 
        if (!mapping) {
                /* Anonymous page without mapping */
@@ -442,8 +443,10 @@ int folio_migrate_mapping(struct address_space *mapping,
                        folio_set_swapcache(newfolio);
                        newfolio->private = folio_get_private(folio);
                }
+               entries = nr;
        } else {
                VM_BUG_ON_FOLIO(folio_test_swapcache(folio), folio);
+               entries = 1;
        }
 
        /* Move dirty while page refs frozen and newpage not yet exposed */
@@ -453,7 +456,11 @@ int folio_migrate_mapping(struct address_space *mapping,
                folio_set_dirty(newfolio);
        }
 
-       xas_store(&xas, newfolio);
+       /* Swap cache still stores N entries instead of a high-order entry */
+       for (i = 0; i < entries; i++) {
+               xas_store(&xas, newfolio);
+               xas_next(&xas);
+       }
 
        /*
         * Drop cache reference from old page by unfreezing