On 19 Sep 2019, at 9:00, James Harvey wrote: > For a really long time (years?) if you forced NFS v4 only, you could > mask a lot of unnecessary services. > > In /etc/nfs.conf, in "[nfsd] I've been able to set "vers3=n", and then > mask the following services: > * gssproxy > * nfs-blkmap > * rpc-statd > * rpcbind (service & socket) > > Upgrading from 5.2.14 to 5.3.0, nfs-server.service (rpc.nfsd) has > exactly a 5 minute delay, and sometimes longer. A bisect ends on: 4f8943f80883 SUNRPC: Replace direct task wakeups from softirq context That commit changed the way we pull the error from the socket, previously we'd wake the task with whatever error is in sk_err from xs_error_report(), but now we use SO_ERROR - but that's only after possibly running through xs_wake_disconnect which forces a closure which can change sk_err. So, I think xs_error_report sees ECONNREFUSED, but we wake tasks with ENOTCONN, and the client machine spins us back around again to reconnect, we do this until things time out. I'll send a patch to revert to the previous behavior of waking tasks with the error as it was in xs_error_report by copying it over to the sock_xprt struct and waking the tasks with that value. There's another subtle change here besides that race: SO_ERROR can return the socket's soft error, not just what's in sk_err. That can be fun things like EINVAL if routing lookups fail.. Ben
