On Tue, Mar 20, 2007 at 01:19:09PM +0100, Jan Kara wrote: > On Tue 20-03-07 12:31:51, Jarek Poplawski wrote: > > On Tue, Mar 20, 2007 at 12:22:53PM +0100, Jarek Poplawski wrote: > > > On Tue, Mar 20, 2007 at 12:17:01PM +0100, Jarek Poplawski wrote: > > > ... > > > > IMHO lockdep found that two locks are taken in different order: > > > > > > > > -> #1: 1) tty_mutex in con_console() 2) dqptr_sem (somewhere later) > > > > -> #0: 1) dqptr_sem 2) tty_console in dquot_alloc_space() with > > > > print_warning() > > > > Once more - should be: > > -> #1: 1) tty_mutex in con_close() 2) dqptr_sem (somewhere later) > > -> #0: 1) dqptr_sem 2) tty_mutex in dquot_alloc_space() with > > print_warning() > Yes, I was looking at it. Hmm, we can possibly get rid of tty_mutex being > acquired under dqptr_sem in quota code. But looking at the path from > con_close() there's another inversion with i_mutex which is also acquired > along the path for sysfs. And we can hardly get rid of it in the quota code. > Now none of these is a real deadlock as quota should never call > print_warning() for sysfs (it doesn't use quota) but still it's nasty. I > suppose tty_mutex is above i_mutex because of those sysfs calls and it > seems sysfs must be called under tty_mutex because of races with > init_dev(). So it's not easy to get rid of that dependency either.
I wonder if this cannot be done with a workqueue (message to a buffer, maybe after try_lock on tty_mutex) and BTW isn't there any "modern" way to queue console messages like these? Jarek P. - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
