From: Wei Yang richardw.yang@linux.intel.com Subject: mm/migrate.c: also overwrite error when it is bigger than zero

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.

Link: http://lkml.kernel.org/r/20200119065753.21694-1-richardw.yang@linux.intel.co... 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@linux.intel.com Acked-by: Yang Shi yang.shi@linux.alibaba.com Cc: John Hubbard jhubbard@nvidia.com Cc: Vlastimil Babka vbabka@suse.cz Cc: Christoph Lameter cl@linux.com Cc: Michal Hocko mhocko@kernel.org Cc: stable@vger.kernel.org Signed-off-by: Andrew Morton akpm@linux-foundation.org ---

mm/migrate.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/mm/migrate.c~mm-migratec-also-overwrite-error-when-it-is-bigger-than-zero +++ a/mm/migrate.c @@ -1676,7 +1676,7 @@ out_flush: 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; _