On Thu, Feb 19, 2009 at 12:02:23PM +0900, Kiyoshi Ueda wrote: > Hi Christof, > > On 2009/02/18 23:21 +0900, Christof Schmitt wrote: > > > From: Christof Schmitt <christof.schmitt@xxxxxxxxxx> > > > > > > Testing with request based dm multipathing and lock dependency checking > > > revealed this problem. Fix this by disabling interrupts when acquiring the > > > map_lock from the ioctl call in __bind and __unbind. > > > > > > It seems that the problem has been introduced with this patch: > > > http://lkml.indiana.edu/hypermail/linux/kernel/0810.0/1067.html > > Thank you for your testing request-based dm-multipath and the patch. > > Attached is a patch to fix it. > Since request-based dm gets map_lock after taking queue_lock with > interrupt disabled, we have to use save/restore variant. > (By the way, although lockdep warns the deadlock possibility, currently > there should be no such code path in request-based dm where request_fn > is called from the interrupt context.) I was checking for other locking problems when this warning from lockdep showed up. While i agree that it is only a problem in theory, it deserves fixing to continue using lockdep. > I have done simple build and boot testings, but haven't done other > testings (e.g. stress testing) yet. > I will include this patch to the next update after such testings. Thanks for the updated patch. I will include this one in future tests. -- Christof Schmitt -- dm-devel mailing list dm-devel@xxxxxxxxxx https://www.redhat.com/mailman/listinfo/dm-devel
