On Tue, 09 Sep 2025, Scott Mayhew wrote:
> In 91da135f ("systemd unit files: fix up dependencies on rpcbind"),
> Neil laid out the rationale for how the nfs services should define their
> dependencies on rpcbind. In a nutshell:
>
> 1. Dependencies should only be defined using rpcbind.socket
> 2. Ordering for dependencies should only be defined usint "After="
> 3. nfs-server.service should use "Wants=rpcbind.socket", to allow
> rpcbind.socket to be masked in NFSv4-only setups.
> 4. rpc-statd.service should use "Requires=rpcbind.socket", as rpc.statd
> is useless if it can't register with rpcbind.
>
> Then in https://bugzilla.redhat.com/show_bug.cgi?id=2100395, Ben noted
> that due to the way the dependencies are ordered, when 'systemctl stop
> rpcbind.socket' is run, systemd first sends SIGTERM to rpcbind, then
> SIGTERM to rpc.statd. On SIGTERM, rpcbind tears down /var/run/rpcbind.sock.
> However, rpc-statd on SIGTERM attempts to unregister from rpcbind. This
> results in a long delay:
>
> [root@rawhide ~]# time systemctl restart rpcbind.socket
>
> real 1m0.147s
> user 0m0.004s
> sys 0m0.003s
>
> 8a835ceb ("rpc-statd.service: Stop rpcbind and rpc.stat in an exit race")
> fixed this by changing the dependency in rpc-statd.service to use
> "After=rpcbind.service", bending rule #1 from above.
>
> Yongcheng recently noted that when runnnig the following test:
>
> [root@rawhide ~]# for i in `seq 10`; do systemctl reset-failed; \
> systemctl stop rpcbind rpcbind.socket ; systemctl restart nfs-server ; \
> systemctl status rpc-statd; done
>
> rpc-statd.service would often fail to start:
>
> × rpc-statd.service - NFS status monitor for NFSv2/3 locking.
> Loaded: loaded (/usr/lib/systemd/system/rpc-statd.service; enabled-runtime; preset: disabled)
> Drop-In: /usr/lib/systemd/system/service.d
> └─10-timeout-abort.conf
> Active: failed (Result: exit-code) since Fri 2025-09-05 18:01:15 EDT; 229ms ago
> Duration: 228ms
> Invocation: bafb2bb00761439ebc348000704e8fbb
> Docs: man:rpc.statd(8)
> Process: 29937 ExecStart=/usr/sbin/rpc.statd (code=exited, status=1/FAILURE)
> Mem peak: 1.5M
> CPU: 7ms
>
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Version 2.8.2 starting
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Flags: TI-RPC
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Failed to register (statd, 1, udp): svc_reg() err: RPC: Remote system error - Connection refused
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Failed to register (statd, 1, tcp): svc_reg() err: RPC: Success
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Failed to register (statd, 1, udp6): svc_reg() err: RPC: Success
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: Failed to register (statd, 1, tcp6): svc_reg() err: RPC: Success
> Sep 05 18:01:15 rawhide.smayhew.test rpc.statd[29938]: failed to create RPC listeners, exiting
> Sep 05 18:01:15 rawhide.smayhew.test systemd[1]: rpc-statd.service: Control process exited, code=exited, status=1/FAILURE
> Sep 05 18:01:15 rawhide.smayhew.test systemd[1]: rpc-statd.service: Failed with result 'exit-code'.
> Sep 05 18:01:15 rawhide.smayhew.test systemd[1]: Failed to start rpc-statd.service - NFS status monitor for NFSv2/3 locking..
>
> Define the dependency on both rpcbind.service and rpcbind.socket. As
> Neil explains:
>
> "After" declarations only have effect if the units are in the same
> transaction. If the Unit is not being started or stopped, the After
> declaration has no effect.
>
> So on startup, this will ensure rpcbind.socket is started before
> rpc-statd.service. On shutdown in a transaction that stops both
> rpc-statd.service and rpcbind.service, rpcbind.service won't be
> stopped until after rpc-statd.service is stopped.
>
> Signed-off-by: Scott Mayhew <smayhew@xxxxxxxxxx>
Reviewed-by: NeilBrown <neil@xxxxxxxxxx>
Thanks,
NeilBrown
> ---
> systemd/rpc-statd.service | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
> diff --git a/systemd/rpc-statd.service b/systemd/rpc-statd.service
> index 660ed861..96fd500d 100644
> --- a/systemd/rpc-statd.service
> +++ b/systemd/rpc-statd.service
> @@ -6,7 +6,7 @@ Conflicts=umount.target
> Requires=nss-lookup.target rpcbind.socket
> Wants=network-online.target
> Wants=rpc-statd-notify.service
> -After=network-online.target nss-lookup.target rpcbind.service
> +After=network-online.target nss-lookup.target rpcbind.service rpcbind.socket
>
> PartOf=nfs-utils.service
> IgnoreOnIsolate=yes
> --
> 2.50.1
>
>
