[v4,11/14] ceph: allow idmapped setattr inode op

From: Christian Brauner <christian.brauner@ubuntu.com>

Enable __ceph_setattr() to handle idmapped mounts. This is just a matter
of passing down the mount's idmapping.

Cc: Xiubo Li <xiubli@redhat.com>
Cc: Jeff Layton <jlayton@kernel.org>
Cc: Ilya Dryomov <idryomov@gmail.com>
Cc: ceph-devel@vger.kernel.org
Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
[ adapted to b27c82e12965 ("attr: port attribute changes to new types") ]
Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
---
v4:
	- introduced fsuid/fsgid local variables
v3:
	- reworked as Christian suggested here:
	https://lore.kernel.org/lkml/20230602-vorzeichen-praktikum-f17931692301@brauner/
---
 fs/ceph/inode.c | 20 ++++++++++++--------
 1 file changed, 12 insertions(+), 8 deletions(-)

On Thu, Jun 8, 2023 at 4:50 AM Xiubo Li <xiubli@redhat.com> wrote:
>
>
> On 6/8/23 02:09, Alexander Mikhalitsyn wrote:
> > From: Christian Brauner <christian.brauner@ubuntu.com>
> >
> > Enable __ceph_setattr() to handle idmapped mounts. This is just a matter
> > of passing down the mount's idmapping.
> >
> > Cc: Xiubo Li <xiubli@redhat.com>
> > Cc: Jeff Layton <jlayton@kernel.org>
> > Cc: Ilya Dryomov <idryomov@gmail.com>
> > Cc: ceph-devel@vger.kernel.org
> > Signed-off-by: Christian Brauner <christian.brauner@ubuntu.com>
> > [ adapted to b27c82e12965 ("attr: port attribute changes to new types") ]
> > Signed-off-by: Alexander Mikhalitsyn <aleksandr.mikhalitsyn@canonical.com>
> > ---
> > v4:
> >       - introduced fsuid/fsgid local variables
> > v3:
> >       - reworked as Christian suggested here:
> >       https://lore.kernel.org/lkml/20230602-vorzeichen-praktikum-f17931692301@brauner/
> > ---
> >   fs/ceph/inode.c | 20 ++++++++++++--------
> >   1 file changed, 12 insertions(+), 8 deletions(-)
> >
> > diff --git a/fs/ceph/inode.c b/fs/ceph/inode.c
> > index bcd9b506ec3b..ca438d1353b2 100644
> > --- a/fs/ceph/inode.c
> > +++ b/fs/ceph/inode.c
> > @@ -2052,31 +2052,35 @@ int __ceph_setattr(struct mnt_idmap *idmap, struct inode *inode,
> >       dout("setattr %p issued %s\n", inode, ceph_cap_string(issued));
> >
> >       if (ia_valid & ATTR_UID) {
> > +             kuid_t fsuid = from_vfsuid(idmap, i_user_ns(inode), attr->ia_vfsuid);
> > +
> >               dout("setattr %p uid %d -> %d\n", inode,
> >                    from_kuid(&init_user_ns, inode->i_uid),
> >                    from_kuid(&init_user_ns, attr->ia_uid));
> >               if (issued & CEPH_CAP_AUTH_EXCL) {
> > -                     inode->i_uid = attr->ia_uid;
> > +                     inode->i_uid = fsuid;
> >                       dirtied |= CEPH_CAP_AUTH_EXCL;
> >               } else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
> > -                        !uid_eq(attr->ia_uid, inode->i_uid)) {
> > +                        !uid_eq(fsuid, inode->i_uid)) {
> >                       req->r_args.setattr.uid = cpu_to_le32(
> > -                             from_kuid(&init_user_ns, attr->ia_uid));
> > +                             from_kuid(&init_user_ns, fsuid));
> >                       mask |= CEPH_SETATTR_UID;
> >                       release |= CEPH_CAP_AUTH_SHARED;
> >               }
> >       }
> >       if (ia_valid & ATTR_GID) {
> > +             kgid_t fsgid = from_vfsgid(idmap, i_user_ns(inode), attr->ia_vfsgid);
> > +
> >               dout("setattr %p gid %d -> %d\n", inode,
> >                    from_kgid(&init_user_ns, inode->i_gid),
> >                    from_kgid(&init_user_ns, attr->ia_gid));
> >               if (issued & CEPH_CAP_AUTH_EXCL) {
> > -                     inode->i_gid = attr->ia_gid;
> > +                     inode->i_gid = fsgid;
> >                       dirtied |= CEPH_CAP_AUTH_EXCL;
> >               } else if ((issued & CEPH_CAP_AUTH_SHARED) == 0 ||
> > -                        !gid_eq(attr->ia_gid, inode->i_gid)) {
> > +                        !gid_eq(fsgid, inode->i_gid)) {
> >                       req->r_args.setattr.gid = cpu_to_le32(
> > -                             from_kgid(&init_user_ns, attr->ia_gid));
> > +                             from_kgid(&init_user_ns, fsgid));
> >                       mask |= CEPH_SETATTR_GID;
> >                       release |= CEPH_CAP_AUTH_SHARED;
> >               }
> > @@ -2241,7 +2245,7 @@ int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
> >       if (ceph_inode_is_shutdown(inode))
> >               return -ESTALE;
> >
> > -     err = setattr_prepare(&nop_mnt_idmap, dentry, attr);
> > +     err = setattr_prepare(idmap, dentry, attr);
> >       if (err != 0)
> >               return err;
> >
> > @@ -2256,7 +2260,7 @@ int ceph_setattr(struct mnt_idmap *idmap, struct dentry *dentry,
> >       err = __ceph_setattr(idmap, inode, attr);
> >
> >       if (err >= 0 && (attr->ia_valid & ATTR_MODE))
> > -             err = posix_acl_chmod(&nop_mnt_idmap, dentry, attr->ia_mode);
> > +             err = posix_acl_chmod(idmap, dentry, attr->ia_mode);
> >
> >       return err;
> >   }

Hi Xiubo,

>
> You should also do 'req->r_mnt_idmap = idmap;' for sync setattr request.
>
> the setattr will just cache the change locally in client side if the 'x'
> caps are issued and returns directly or will set a sync setattr reqeust.

Have done in v5:
("ceph: pass idmap to __ceph_setattr")
https://lore.kernel.org/lkml/20230608154256.562906-8-aleksandr.mikhalitsyn@canonical.com/

Kind regards,
Alex

>
> Thanks
>
> - Xiubo
>