On Wed, Apr 11, 2012 at 11:17:16AM +0800, Ren Mingxin wrote: > On 04/09/2012 03:53 PM, Michael S. Tsirkin wrote: > >On Wed, Mar 28, 2012 at 11:40:33AM +0800, Ren Mingxin wrote: > >>On guest with upstream's kernel(3.3.0-rc7), I > >>mounted virtblk as: > >> a) # mkfs /dev/vda > >> b) # mount /dev/vda /mnt > >> c) # cd /mnt > >> > >>Then I did hotplug for virtblk via virsh on host as: > >> a) # sudo virsh detach-disk guest vda > >> b) # sudo virsh attach-disk guest /media/data/test.img vda > >> > >>I encountered guest's kernel panic (*probability* > >>*event*)whose backtrace liked this: > >Any news here? Managed to trace? > > Sorry, I had a leave last week. > > >Does this still happen with 3.4-rc2? > > I retested this with 3.4-rc2, but the panic couldn't be reproduced. > (Last time, It seemed that the upstream's kernel was 3.3-rc7) > > >There's a chance you are hitting a race fixed by > >4678d6f970c2f7c0cbfefc0cc666432d153b321b. > > > >If it's still not fixed it might make sense to enable slab debugging - > >we might have a use after free here. > > > > I don't think the below commit has fixed this panic issue, for it is > included > in my last test environment(3.3-rc7). > 4678d6f970c2f7c0cbfefc0cc666432d153b321b > > Now, I'd find which commit makes sense. Great, thanks very much. I do suggest slab debugging if the race reproduces for you with it enabled - reducing the chance random struct rearrangements hide the bug. > -- > Thanks, > Ren -- To unsubscribe from this list: send the line "unsubscribe linux-hotplug" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
