On Tue, Nov 05, 2019 at 08:05:48PM +1100, Aleksa Sarai wrote: Minor nit here - I'd split "move the conditional call of set_root() into nd_jump_root()" into a separate patch before that one. Makes for fewer distractions in this one. I'd probably fold "and be ready for errors other than -ECHILD" into the same preliminary patch. > + /* Not currently safe for scoped-lookups. */ > + if (unlikely(nd->flags & LOOKUP_IS_SCOPED)) > + return ERR_PTR(-EXDEV); Also a candidate for doing in nd_jump_link()... > @@ -1373,8 +1403,11 @@ static int follow_dotdot_rcu(struct nameidata *nd) > struct inode *inode = nd->inode; > > while (1) { > - if (path_equal(&nd->path, &nd->root)) > + if (path_equal(&nd->path, &nd->root)) { > + if (unlikely(nd->flags & LOOKUP_BENEATH)) > + return -EXDEV; Umm... Are you sure it's not -ECHILD?