On Mon, Nov 6, 2017 at 2:33 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote: > On Mon, Nov 06, 2017 at 02:15:44PM +0100, Jan Kara wrote: > >> > Should we annotate these inodes with different lock types? Or use >> > nesting annotations? >> >> Well, you'd need to have a completely separate set of locking classes for >> each filesystem to avoid false positives like these. And that would >> increase number of classes lockdep has to handle significantly. So I'm not >> sure it's really worth it... > > Especially when you consider that backing file might be on a filesystem > that lives on another loop device. *All* per-{device,fs} locks involved > would need classes split that way... This crashes our test machines left and right. We've seen 100000+ of these crashes. We need to do at least something. Can we disable all checking of these mutexes if they inherently have positives? +Ingo, Peter, maybe you have some suggestions of how to fight this lockdep false positives. Full thread is here: https://groups.google.com/forum/#!msg/syzkaller-bugs/NJ_4llH84XI/c7M9jNLTAgAJ -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>