king for a
> >          * name on a file system that does not require normalization
> >          * or case folding.  We can also look there if we happen to be
> >          * on a non-normalizing, mixed sensitivity file system IF we
> >          * are looking for the exact name (which is always the case on
> >          * FreeBSD).
> >          */
> >         zfsvfs->z_use_namecache =3D !zfsvfs->z_norm ||
> >             ((zfsvfs->z_case =3D=3D ZFS_CASE_MIXED) &&
> >             !(zfsvfs->z_norm & ~U8_TEXTPREP_TOUPPER));
> >
> >
> > The call to cache_vop_rename() which causes the panic is not protected =
by an =E2=80=9Cif (zfsvfs->z_use_namecache)=E2=80=9D, unlike the rest of th=
e code that uses that to decide whether or not to use the namecache.
> >
> > Elsewhere in zfs_vnops_os.c, there is another call to a cache_vop* func=
tion, which is protected by a test:
> >
> >         if (zfsvfs->z_use_namecache)
> >                 cache_vop_rmdir(dvp, vp);
> >
> > It seems to me that this patch could resolve the problem. Does this see=
m reasonable?
> >
> > --- a/src/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c    2=
026-03-28 20:55:06.000000000 1100
> > +++ b/src/sys/contrib/openzfs/module/os/freebsd/zfs/zfs_vnops_os.c    2=
026-03-28 20:55:06.000000000 1100
> > @@ -3524,7 +3524,7 @@
> >                                   ZRENAMING, NULL));
> >                       }
> >               }
> > -             if (error =3D=3D 0) {
> > +             if (error =3D=3D 0 && zfsvfs->z_use_namecache) {
> >                       cache_vop_rename(sdvp, *svpp, tdvp, *tvpp, scnp, =
tcnp);
> >               }
> >       }
> >
>
> Yes, but please test.
> If works for you, please either create a Github PR or a review on the
> FreeBSD' phab.
I find a Pull Request for OpenZFS on github tends to get mav@'s
attention pretty quickly, so I think that is the better way to go.

rick

>