From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754125AbcITMFE (ORCPT ); Tue, 20 Sep 2016 08:05:04 -0400 Received: from ozlabs.org ([103.22.144.67]:41747 "EHLO ozlabs.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753080AbcITMFD (ORCPT ); Tue, 20 Sep 2016 08:05:03 -0400 From: Michael Ellerman To: Andrew Morton Cc: Jan Kara , Guenter Roeck , "linux-kernel\@vger.kernel.org" Subject: Re: Crashes in next-20160915 (BUG at fs/notify/notification.c:66!) In-Reply-To: <20160919181342.ef41286b6cbd45a27a5968a7@linux-foundation.org> References: <20160916064521.GF24269@quack2.suse.cz> <6ae57328-ab25-8798-51f9-9a30d9c2af70@roeck-us.net> <20160916124948.GG24269@quack2.suse.cz> <87vaxrs7ec.fsf@concordia.ellerman.id.au> <20160919181342.ef41286b6cbd45a27a5968a7@linux-foundation.org> User-Agent: Notmuch/0.21 (https://notmuchmail.org) Date: Tue, 20 Sep 2016 22:05:00 +1000 Message-ID: <87k2e6sro3.fsf@concordia.ellerman.id.au> MIME-Version: 1.0 Content-Type: text/plain Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Andrew Morton writes: > On Tue, 20 Sep 2016 11:10:35 +1000 Michael Ellerman wrote: >> Jan Kara 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. > 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. cheers