The do_move_pages_to_node() might return > 0 value, the number of pages that are not migrated, then the value will be returned to userspace directly. But, move_pages() syscall would just return 0 or errno. So, we need reset the return value to 0 for such case as what pre-v4.17 did.
Fixes: a49bd4d71637 ("mm, numa: rework do_pages_move") Cc: Michal Hocko mhocko@suse.com Cc: Wei Yang richardw.yang@linux.intel.com Cc: stable@vger.kernel.org [4.17+] Signed-off-by: Yang Shi yang.shi@linux.alibaba.com --- mm/migrate.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)
diff --git a/mm/migrate.c b/mm/migrate.c index 86873b6..3e75432 100644 --- a/mm/migrate.c +++ b/mm/migrate.c @@ -1659,8 +1659,11 @@ static int do_pages_move(struct mm_struct *mm, nodemask_t task_nodes, goto out_flush;
err = do_move_pages_to_node(mm, &pagelist, current_node); - if (err) + if (err) { + if (err > 0) + err = 0; goto out; + } if (i > start) { err = store_status(status, start, current_node, i - start); if (err)