On Mon, Sep 9, 2024 at 2:57 PM Christian Brauner <brauner@xxxxxxxxxx> wrote: > > On Fri, Sep 06, 2024 at 04:34:52PM GMT, Alexander Mikhalitsyn wrote: > > Link: https://lore.kernel.org/linux-fsdevel/20240904-baugrube-erhoben-b3c1c49a2645@brauner/ > > Suggested-by: Christian Brauner <brauner@xxxxxxxxxx> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@xxxxxxxxxxxxx> > > --- > > fs/mnt_idmapping.c | 22 ++++++++++++++++++++-- > > include/linux/mnt_idmapping.h | 1 + > > 2 files changed, 21 insertions(+), 2 deletions(-) > > > > diff --git a/fs/mnt_idmapping.c b/fs/mnt_idmapping.c > > index 3c60f1eaca61..cbca6500848e 100644 > > --- a/fs/mnt_idmapping.c > > +++ b/fs/mnt_idmapping.c > > @@ -32,6 +32,15 @@ struct mnt_idmap nop_mnt_idmap = { > > }; > > EXPORT_SYMBOL_GPL(nop_mnt_idmap); > > > > +/* > > + * Carries the invalid idmapping of a full 0-4294967295 {g,u}id range. > > + * This means that all {g,u}ids are mapped to INVALID_VFS{G,U}ID. > > + */ > > +struct mnt_idmap invalid_mnt_idmap = { > > + .count = REFCOUNT_INIT(1), > > +}; > > +EXPORT_SYMBOL_GPL(invalid_mnt_idmap); > > + > > /** > > * initial_idmapping - check whether this is the initial mapping > > * @ns: idmapping to check > > @@ -75,6 +84,8 @@ vfsuid_t make_vfsuid(struct mnt_idmap *idmap, > > > > if (idmap == &nop_mnt_idmap) > > return VFSUIDT_INIT(kuid); > > + if (idmap == &invalid_mnt_idmap) > > + return INVALID_VFSUID; > > Could possibly deserve an: > > if (unlikely(idmap == &invalid_mnt_idmap)) > return INVALID_VFSUID; > > and technically I guess we could also do: > > if (likely(idmap == &nop_mnt_idmap)) > return VFSUIDT_INIT(kuid); > > but not that relevant for this patch. Yeah, I'm happy to submit that change (if you don't mind) a bit later when this will be merged, cause in this case we can add this likely()/unlikely() at once for both nop_mnt_idmap/invalid_mnt_idmap. Kind regards, Alex
