On Tue 20-09-16 22:05:00, Michael Ellerman wrote:
> Andrew Morton <a...@linux-foundation.org> writes:
> > On Tue, 20 Sep 2016 11:10:35 +1000 Michael Ellerman <m...@ellerman.id.au>
> > wrote:
> >> Jan Kara <j...@suse.cz> writes:
> >> >
> >> > Right, that was the problem. spin_is_locked() without
> >> > CONFIG_SPINLOCK_DEBUG
> >> > returns always 0.
> >>
> >> Can we get this fixed soon please? It's breaking all my CI runs.
> >
> > It should be fixed in next -next.
>
> Great thanks.
>
> I did search LKML to see if Jan had sent a fix but I guess I missed it.
I didn't send the fix to LKML but only to linux-fsdevel...
> > diff -puN
> > fs/notify/fanotify/fanotify_user.c~fsnotify-convert-notification_mutex-to-a-spinlock-fix
> > fs/notify/fanotify/fanotify_user.c
> > ---
> > a/fs/notify/fanotify/fanotify_user.c~fsnotify-convert-notification_mutex-to-a-spinlock-fix
> > +++ a/fs/notify/fanotify/fanotify_user.c
> > @@ -54,7 +54,8 @@ struct kmem_cache *fanotify_perm_event_c
> > static struct fsnotify_event *get_one_event(struct fsnotify_group *group,
> > size_t count)
> > {
> > - BUG_ON(!spin_is_locked(&group->notification_lock));
> > + BUG_ON(IS_ENABLED(CONFIG_SMP) &&
> > + !spin_is_locked(&group->notification_lock));
>
> I thought lockdep_assert_held() was preferred for checks like this that
> are purely sanity checking, ie. not part of the algorithm.
As pointed out by other guy, assert_spin_locked() is probably the right way
to do it (it's a wrapper that does essentially what I did here). Somehow I
missed that when looking for the right fix.
Honza
--
Jan Kara <j...@suse.com>
SUSE Labs, CR
