On Tue, Sep 18, 2007 at 10:36:32AM +0400, Pavel Emelyanov wrote: > J. Bruce Fields wrote: > > I would also prefer a locking scheme that didn't rely on the BKL. That > > said, except for this race: > > I would as well :) But I don't know the locking code good enough to > start fixing. Besides, even if I send a patch series that handles this, > I don't think that anyone will accept it, due to "this changes too much > code", "can you prove you fixed all the places" and so on...
Several people have expressed interest in a locking scheme for locks.c (and probably lockd) that doesn't depend on BKL, so I don't think it would be ignored. But, yes, it would have to be done very carefully; there have been at least one or two previous attempts that failed. > >>> (For example, my impression is that a mandatory lock can be applied just > >>> after the locks_mandatory_area() checks but before the io actually > >>> completes.) > > > > ... I'm not aware of other races in the existing file-locking code. It > > sounds like you might be. Could you give specific examples? > > Well, there's a long standing BUG in leases code - when we made all the > checks in inserting lease, we call the locks_alloc_lock() and may fall > asleep. Bu after the wakeup nobody re-checks for the things to change. Ouch, yes, you're right. > I suspect there are other bad places. OK. Thanks in advance for finding any! --b. - 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/
