Re: [PATCH v9 04/10] namei: split out nd->dfd handling to dirfd_path_init

Al Viro
2019-07-12T04:20:50Z

On Sun, Jul 07, 2019 at 12:57:31AM +1000, Aleksa Sarai wrote:
> Previously, path_init's handling of *at(dfd, ...) was only done once,
> but with LOOKUP_BENEATH (and LOOKUP_IN_ROOT) we have to parse the
> initial nd->path at different times (before or after absolute path
> handling) depending on whether we have been asked to scope resolution
> within a root.

> if (*s == '/') {
> - set_root(nd);
> - if (likely(!nd_jump_root(nd)))
> - return s;
> - return ERR_PTR(-ECHILD);

> + if (likely(!nd->root.mnt))
> + set_root(nd);

How can we get there with non-NULL nd->root.mnt, when LOOKUP_ROOT case
has been already handled by that point?

> + error = nd_jump_root(nd);
> + if (unlikely(error))
> + s = ERR_PTR(error);