On Fri, Apr 09, 2021 at 09:15:06AM +0800, Ian Kent wrote:
> + parent = kernfs_dentry_node(dentry->d_parent);
> + if (parent) {
> + const void *ns = NULL;
> +
> + if (kernfs_ns_enabled(parent))
> + ns = kernfs_info(dentry->d_parent->d_sb)->ns;
For any dentry d, we have d->d_parent->d_sb == d->d_sb. All the time.
If you ever run into the case where that would not be true, you've found
a critical bug.
> + kn = kernfs_find_ns(parent, dentry->d_name.name, ns);
> + if (kn)
> + goto out_bad;
> + }
Umm... What's to prevent a race with successful rename(2)? IOW, what's
there to stabilize ->d_parent and ->d_name while we are in that function?
