Messages in this thread | | | Date | Tue, 16 Nov 2021 07:57:09 +0100 | From | Jiri Pirko <> | Subject | Re: [PATCH net-next] devlink: Require devlink lock during device reload |
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Mon, Nov 15, 2021 at 04:09:31PM CET, jgg@nvidia.com wrote: >On Mon, Nov 15, 2021 at 03:42:58PM +0100, Jiri Pirko wrote: > >> >Sorry, I don't agree that registering a net notifier in an aux device >> >probe function is non-standard or wrong. >> >> Listening to events which happen in different namespaces and react to >> them is the non-standard behaviour which I refered to. If you would not >> need to do it, you could just use netns notofier which would solve your >> issue. You know it. > >Huh? > >It calls the bog standard > > register_netdevice_notifier() > >Like hundreds of other drivers do from their probe functions > >Which does: > >int register_netdevice_notifier(struct notifier_block *nb) >{ > struct net *net; > int err; > > /* Close race with setup_net() and cleanup_net() */ > down_write(&pernet_ops_rwsem); > >And deadlocks because devlink hols the pernet_ops_rwsem when it >triggers reload in some paths. > >There is nothing wrong with a driver doing this standard pattern. > >There is only one place in the entire kernel calling the per-ns >register_netdevice_notifier_dev_net() and it is burred inside another >part of mlx5 for some reason..
Yep. I added it there to solve this deadlock.
> >I believe Parav already looked at using that in rdma and it didn't >work for some reason I've forgotten. > >It is not that we care about events in different namespaces, it is >that rdma, like everything else, doesn't care about namespaces and >wants events from the netdev no matter where it is located.
Wait, so there is no notion of netnamespaces in rdma? I was under impression rdma supports netnamespaces...
> >Jason
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