Re: [PATCH net-next v3 1/4] udp_tunnel: remove rtnl_lock dependency
On Wed, 11 Jun 2025 19:47:54 -0700 Stanislav Fomichev wrote: > > There are multiple entry points to this code, basically each member of > > struct udp_tunnel_nic_ops and the netdev notifiers. In this patch only > > reset and work are locked. I'm a bit confused as to what is the new > > lock protecting :S > > I though that most of the callers are from do_setlink and there we have > rtnl and we grab rtnl+lock during the sync. But that doesn't > address the suspend/resume vs do_setlink race, that's true :-( It's the UDP tunnels that add and remove the ports usually.
Re: [PATCH net-next v3 1/4] udp_tunnel: remove rtnl_lock dependency
On 06/11, Jakub Kicinski wrote: > On Tue, 10 Jun 2025 10:15:19 -0700 Stanislav Fomichev wrote: > > Drivers that are using ops lock and don't depend on RTNL lock > > still need to manage it because udp_tunnel's RTNL dependency. > > Introduce new udp_tunnel_nic_lock and use it instead of > > rtnl_lock. Drop non-UDP_TUNNEL_NIC_INFO_MAY_SLEEP mode from > > udp_tunnel infra (udp_tunnel_nic_device_sync_work needs to > > grab udp_tunnel_nic_lock mutex and might sleep). > > There are multiple entry points to this code, basically each member of > struct udp_tunnel_nic_ops and the netdev notifiers. In this patch only > reset and work are locked. I'm a bit confused as to what is the new > lock protecting :S I though that most of the callers are from do_setlink and there we have rtnl and we grab rtnl+lock during the sync. But that doesn't address the suspend/resume vs do_setlink race, that's true :-( Did not look deep into the notifiers, assuming they are a way to push the info down to the devices (under rtnl) plus trigger the sync work, will take a closer look.
Re: [PATCH net-next v3 1/4] udp_tunnel: remove rtnl_lock dependency
On Tue, 10 Jun 2025 10:15:19 -0700 Stanislav Fomichev wrote: > Drivers that are using ops lock and don't depend on RTNL lock > still need to manage it because udp_tunnel's RTNL dependency. > Introduce new udp_tunnel_nic_lock and use it instead of > rtnl_lock. Drop non-UDP_TUNNEL_NIC_INFO_MAY_SLEEP mode from > udp_tunnel infra (udp_tunnel_nic_device_sync_work needs to > grab udp_tunnel_nic_lock mutex and might sleep). There are multiple entry points to this code, basically each member of struct udp_tunnel_nic_ops and the netdev notifiers. In this patch only reset and work are locked. I'm a bit confused as to what is the new lock protecting :S
