No need to resend! I'll make sure the fixes & cc line get added to the commit
On Thu, Nov 12, 2020 at 9:03 AM J. Bruce Fields <bfields@xxxxxxxxxxxx> wrote:
>
> Looks like this patch got lost, do you need me to resend?
>
> I should also have added a stable cc and a
>
> Fixes: 95ad37f90c33 "NFSv4.2: add client side xattr caching."
>
> --b.
>
> On Wed, Oct 21, 2020 at 10:34:15AM -0400, bfields wrote:
> > From: "J. Bruce Fields" <bfields@xxxxxxxxxx>
> >
> > We forgot to unregister the nfs4_xattr_large_entry_shrinker.
> >
> > That leaves the global list of shrinkers corrupted after unload of the
> > nfs module, after which possibly unrelated code that calls
> > register_shrinker() or unregister_shrinker() gets a BUG() with
> > "supervisor write access in kernel mode".
> >
> > And similarly for the nfs4_xattr_large_entry_lru.
> >
> > Reported-by: Kris Karas <bugs-a17@xxxxxxxxxxxxxxxx>
> > Tested-By: Kris Karas <bugs-a17@xxxxxxxxxxxxxxxx>
> > Signed-off-by: J. Bruce Fields <bfields@xxxxxxxxxx>
> > ---
> > fs/nfs/nfs42xattr.c | 2 ++
> > 1 file changed, 2 insertions(+)
> >
> > diff --git a/fs/nfs/nfs42xattr.c b/fs/nfs/nfs42xattr.c
> > index 86777996cfec..55b44a42d625 100644
> > --- a/fs/nfs/nfs42xattr.c
> > +++ b/fs/nfs/nfs42xattr.c
> > @@ -1048,8 +1048,10 @@ int __init nfs4_xattr_cache_init(void)
> >
> > void nfs4_xattr_cache_exit(void)
> > {
> > + unregister_shrinker(&nfs4_xattr_large_entry_shrinker);
> > unregister_shrinker(&nfs4_xattr_entry_shrinker);
> > unregister_shrinker(&nfs4_xattr_cache_shrinker);
> > + list_lru_destroy(&nfs4_xattr_large_entry_lru);
> > list_lru_destroy(&nfs4_xattr_entry_lru);
> > list_lru_destroy(&nfs4_xattr_cache_lru);
> > kmem_cache_destroy(nfs4_xattr_cache_cachep);
> > --
> > 2.26.2
> >
