Re: [nfs-utils PATCH v2] rpc-statd.service: define dependency on both rpcbind.service and rpcbind.socket

[Steve Dickson <steved@redhat.com>]

On 9/9/25 9:17 AM, 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@redhat.com>
Committed... (tag: nfs-utils-2-8-4-rc4)

steved.
> ---
>   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