Ilya Maximets <[email protected]> writes: > Sashiko reports that it is technically possible that we got the device > reference, but by the time we're linking it to the OVS datapath, it > may be already in the process of being deleted. In this case if the > notifier wins the race for RTNL, it will see that the device is not > yet in the OVS datapath (ovs_netdev_get_vport() will fail in the > dp_device_event()) and will do nothing. Then the ovs_netdev_link() > will take the RTNL and link the unregistering device to OVS datapath. > > Eventually, netdev_wait_allrefs_any() will re-broadcast the event and > the device will be properly detached, but it will take at least a > second before that happens, so it's not something we should rely on. > > Let's avoid linking the non-registered device in the first place. > > Note: As per documentation, RTNL doesn't protect the reg_state, but > it actually does for all the state transitions we care about here, > so it should not be necessary to use READ_ONCE or taking the instance > lock. We can still do that, but we have a few more places even in > this file where the reg_state is accessed without those while under > RTNL, and many more places like this across the kernel code, so it > might make more sense to change all of them in a more centralized > fashion in the future, if necessary. > > Fixes: ccb1352e76cf ("net: Add Open vSwitch kernel components.") > Signed-off-by: Ilya Maximets <[email protected]> > ---
Reviewed-by: Aaron Conole <[email protected]> _______________________________________________ dev mailing list [email protected] https://mail.openvswitch.org/mailman/listinfo/ovs-dev
