Re: [PATCH] vfs: move_mount: reject moving kernel internal mounts

Al Viro
2019-07-01T11:19:58Z

On Mon, Jul 01, 2019 at 08:38:10AM +0100, David Howells wrote:
> Al Viro <viro@zeniv.linux.org.uk> wrote:
>
> > /* The thing moved must be mounted... */
> > if (!is_mounted(old_path->mnt))
> > goto out;
>
> Um... Doesn't that stuff up fsmount()?

Nope - check is_mounted() definition. Stuff in anon namespace
*is* mounted there, so that's not a problem.

FWIW, is_mounted() would've been better off spelled as
ns != NULL && ns != MNT_NS_INTERNAL; the use of IS_ERR_OR_NULL
in there works, but is unidiomatic and I don't think it yields
better code...