| Message ID | 20240906143453.179506-2-aleksandr.mikhalitsyn@canonical.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | [v1,1/3] fs/fuse: introduce and use fuse_simple_idmap_request() helper | expand |
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@kernel.org> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > --- > 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.
On Mon, Sep 09, 2024 at 02:57:51PM GMT, Christian Brauner 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@kernel.org> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > > --- > > 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. Forgot: Reviewed-by: Christian Brauner <brauner@kernel.org>
On Mon, Sep 9, 2024 at 2:57 PM Christian Brauner <brauner@kernel.org> 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@kernel.org> > > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> > > --- > > 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
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; if (initial_idmapping(fs_userns)) uid = __kuid_val(kuid); else @@ -112,6 +123,8 @@ vfsgid_t make_vfsgid(struct mnt_idmap *idmap, if (idmap == &nop_mnt_idmap) return VFSGIDT_INIT(kgid); + if (idmap == &invalid_mnt_idmap) + return INVALID_VFSGID; if (initial_idmapping(fs_userns)) gid = __kgid_val(kgid); else @@ -140,6 +153,8 @@ kuid_t from_vfsuid(struct mnt_idmap *idmap, if (idmap == &nop_mnt_idmap) return AS_KUIDT(vfsuid); + if (idmap == &invalid_mnt_idmap) + return INVALID_UID; uid = map_id_up(&idmap->uid_map, __vfsuid_val(vfsuid)); if (uid == (uid_t)-1) return INVALID_UID; @@ -167,6 +182,8 @@ kgid_t from_vfsgid(struct mnt_idmap *idmap, if (idmap == &nop_mnt_idmap) return AS_KGIDT(vfsgid); + if (idmap == &invalid_mnt_idmap) + return INVALID_GID; gid = map_id_up(&idmap->gid_map, __vfsgid_val(vfsgid)); if (gid == (gid_t)-1) return INVALID_GID; @@ -296,7 +313,7 @@ struct mnt_idmap *alloc_mnt_idmap(struct user_namespace *mnt_userns) */ struct mnt_idmap *mnt_idmap_get(struct mnt_idmap *idmap) { - if (idmap != &nop_mnt_idmap) + if (idmap != &nop_mnt_idmap && idmap != &invalid_mnt_idmap) refcount_inc(&idmap->count); return idmap; @@ -312,7 +329,8 @@ EXPORT_SYMBOL_GPL(mnt_idmap_get); */ void mnt_idmap_put(struct mnt_idmap *idmap) { - if (idmap != &nop_mnt_idmap && refcount_dec_and_test(&idmap->count)) + if (idmap != &nop_mnt_idmap && idmap != &invalid_mnt_idmap && + refcount_dec_and_test(&idmap->count)) free_mnt_idmap(idmap); } EXPORT_SYMBOL_GPL(mnt_idmap_put); diff --git a/include/linux/mnt_idmapping.h b/include/linux/mnt_idmapping.h index cd4d5c8781f5..b1b219bc3422 100644 --- a/include/linux/mnt_idmapping.h +++ b/include/linux/mnt_idmapping.h @@ -9,6 +9,7 @@ struct mnt_idmap; struct user_namespace; extern struct mnt_idmap nop_mnt_idmap; +extern struct mnt_idmap invalid_mnt_idmap; extern struct user_namespace init_user_ns; typedef struct {
Link: https://lore.kernel.org/linux-fsdevel/20240904-baugrube-erhoben-b3c1c49a2645@brauner/ Suggested-by: Christian Brauner <brauner@kernel.org> Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com> --- fs/mnt_idmapping.c | 22 ++++++++++++++++++++-- include/linux/mnt_idmapping.h | 1 + 2 files changed, 21 insertions(+), 2 deletions(-)