If we get here after successfully adding page to list, err would be 1 to indicate the page is queued in the list. Current code has two problems: * on success, 0 is not returned * on error, if add_page_for_migratioin() return 1, and the following err1 from do_move_pages_to_node() is set, the err1 is not returned since err is 1 And these behaviors break the user interface. Fixes: e0153fc2c760 ("mm: move_pages: return valid node id in status if the page is already on the target node"). Signed-off-by: Wei Yang <richardw.yang@xxxxxxxxxxxxxxx> --- v2: * put more words to explain the error case --- mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/mm/migrate.c b/mm/migrate.c index 86873b6f38a7..430fdccc733e 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1676,7 +1676,7 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, err1 = do_move_pages_to_node(mm, &pagelist, current_node); if (!err1) err1 = store_status(status, start, current_node, i - start); - if (!err) + if (err >= 0) err = err1; out: return err; -- 2.17.1