On Fri, Mar 31 2017, Scott Mayhew wrote: > These patches aim to make it a little easier to change the mountpoint. > Right now if you change the pipefs-directory in /etc/nfs.conf, you still > need to manually override the dependencies in the systemd unit files in > order for the change to actually work. > > The first patch moves rpc.idmapd's (mostly) undocumented > pipefs-directory from /etc/idmapd.conf to /etc/nfs.conf, which rpc.gssd > already can use for it's pipefs-directory configuration. > > The second patch adds a systemd generator that reads the > pipefs-directory configurations from /etc/nfs.conf, and if they differ > from the default it will automatically 1) create a systemd mount unit > file for the pipefs mountpoint and 2) it will create a drop-in > configuration file to override the Requires= and After= directives for > that service. > > I did run into a bit of a snag though. Depsite overriding the > dependencies for both idmapd and gssd, I wind up with two pipefs > filesystems mounted: > > [root@coeurl ~]# grep pipefs /proc/mounts > sunrpc /var/lib/nfs/rpc_pipefs rpc_pipefs rw,relatime 0 0 > sunrpc /run/rpc_pipefs rpc_pipefs rw,relatime 0 0 > > systemd still shows the dependency on the default pipefs mountpoint: > > [root@coeurl ~]# systemctl list-dependencies --before var-lib-nfs-rpc_pipefs.mount > var-lib-nfs-rpc_pipefs.mount > ● ├─nfs-idmapd.service > ● └─rpc-gssd.service > > as well as the new one: > > [root@coeurl ~]# systemctl list-dependencies --before run-rpc_pipefs.mount > run-rpc_pipefs.mount > ● ├─nfs-idmapd.service > ● └─rpc-gssd.service > > The drop-in configs to override the pipefs mountpoint look correct. I'm > clearing both Requires= and After= before setting them: > > [root@coeurl ~]# cat /run/systemd/generator/nfs-idmapd.service.d/10-pipefs.conf > # Automatically generated by rpc-pipefs-generator > > [Unit] > Requires= > Requires=run-rpc_pipefs.mount > After= > After=run-rpc_pipefs.mount local-fs.target > > [root@coeurl ~]# cat /run/systemd/generator/rpc-gssd.service.d/10-pipefs.conf > # Automatically generated by rpc-pipefs-generator > > [Unit] > Requires= > Requires=run-rpc_pipefs.mount > After= > After=run-rpc_pipefs.mount > > The generated mount unit file also looks correct: > > [root@coeurl ~]# cat /run/systemd/generator/run-rpc_pipefs.mount > # Automatically generated by rpc-pipefs-generator > > [Unit] > Description=RPC Pipe File System > DefaultDependencies=no > After=systemd-tmpfiles-setup.service > Conflicts=umount.target > > [Mount] > What=sunrpc > Where=/run/rpc_pipefs > Type=rpc_pipefs > > systemd shows that the drop-in config was picked up: > > [root@coeurl ~]# systemctl status nfs-idmapd > ● nfs-idmapd.service - NFSv4 ID-name mapping service > Loaded: loaded (/usr/lib/systemd/system/nfs-idmapd.service; static; vendor preset: disabled) > Drop-In: /run/systemd/generator/nfs-idmapd.service.d > └─10-pipefs.conf > Active: active (running) since Fri 2017-03-31 16:54:24 EDT; 5min ago > Process: 27831 ExecStart=/usr/sbin/rpc.idmapd $RPCIDMAPDARGS (code=exited, status=0/SUCCESS) > Main PID: 27832 (rpc.idmapd) > Tasks: 1 (limit: 4915) > CGroup: /system.slice/nfs-idmapd.service > └─27832 /usr/sbin/rpc.idmapd > > and lsof shows that the correct mountpoint is being used: > > [root@coeurl ~]# lsof -p 27832 2>/dev/null | grep pipefs > rpc.idmap 27832 root 10r DIR 0,42 0 103 /run/rpc_pipefs/nfs > > The same for gssd: > > [root@coeurl ~]# systemctl status rpc-gssd > ● rpc-gssd.service - RPC security service for NFS client and server > Loaded: loaded (/usr/lib/systemd/system/rpc-gssd.service; static; vendor preset: disabled) > Drop-In: /run/systemd/generator/rpc-gssd.service.d > └─10-pipefs.conf > Active: active (running) since Fri 2017-03-31 16:54:29 EDT; 6min ago > Process: 27839 ExecStart=/usr/sbin/rpc.gssd $RPCGSSDARGS (code=exited, status=0/SUCCESS) > Main PID: 27840 (rpc.gssd) > Tasks: 1 (limit: 4915) > CGroup: /system.slice/rpc-gssd.service > └─27840 /usr/sbin/rpc.gssd > > [root@coeurl ~]# lsof -p 27840 2>/dev/null | grep pipefs > rpc.gssd 27840 root cwd DIR 0,42 0 24637 /run/rpc_pipefs > rpc.gssd 27840 root 7r DIR 0,42 0 24637 /run/rpc_pipefs > rpc.gssd 27840 root 11u FIFO 0,42 0t0 112 /run/rpc_pipefs/gssd/clntXX/gssd > > So it looks like systemd is using both sets of dependencies, even though > the programs themselves are only looking for what's specified in > /etc/nfs.conf. I'm not sure what to do about that. Maybe remove the > var-lib-nfs-rpc_pipefs.mount unit as well as the dependencies in the > nfs-idmapd.service and rpc-gssd.service files, and have the generator > create those automatically as well? > Towards the end of the systemd.unit man page is the text: Note that dependencies (After=, etc.) cannot be reset to an empty list, so dependencies can only be added in drop-ins. If you want to remove dependencies, you have to override the entire unit. which is consistent with what you discovered. Maybe create a "rpc_pipefs.target" which Requires=var-lib-nfs-rpc_pipefs.mount After=var-lib-nfs-rpc_pipefs.mount and have all the other unit files specified their dependencies against this target. Then your generator would conditionally create a new "rpc_pipefs.target" and matching foo.mount. The new .target would depend in the foo.mount, and the service files would already depend on that. Might work. Thanks, NeilBrown > -Scott > > Scott Mayhew (2): > idmapd: move the pipefs-directory config option to nfs.conf > systemd: add a generator for the rpc_pipefs mountpoint > > .gitignore | 1 + > nfs.conf | 3 + > systemd/Makefile.am | 4 +- > systemd/nfs.conf.man | 9 ++ > systemd/rpc-pipefs-generator.c | 256 +++++++++++++++++++++++++++++++++++++++++ > systemd/rpc-svcgssd.service | 3 +- > utils/idmapd/idmapd.c | 35 +++--- > utils/idmapd/idmapd.man | 19 ++- > 8 files changed, 305 insertions(+), 25 deletions(-) > create mode 100644 systemd/rpc-pipefs-generator.c > > -- > 2.9.3 > > -- > To unsubscribe from this list: send the line "unsubscribe linux-nfs" in > the body of a message to majordomo@vger.kernel.org > More majordomo info at http://vger.kernel.org/majordomo-info.html