Add templated [email protected]

Runs `zfs mount -R <dataset>` at boot, after `zfs mount -a`.
Intended to replace `mountpoint=legacy` in certain mount setups.

Reviewed-by: Brian Behlendorf <[email protected]>
Signed-off-by: Meriel Luna Mittelbach <[email protected]>
Closes #17483

Author: LunarLambda

contrib/debian/openzfs-zfsutils.install

@@ -8,6 +8,7 @@ lib/systemd/system/zfs-import-scan.service
 lib/systemd/system/zfs-import.target
 lib/systemd/system/zfs-load-key.service
 lib/systemd/system/zfs-mount.service
+lib/systemd/system/[email protected]
 lib/systemd/system/[email protected]
 lib/systemd/system/[email protected]
 lib/systemd/system/[email protected]

etc/Makefile.am

@@ -56,6 +56,7 @@ systemdunit_DATA = \
 	%D%/systemd/system/zfs-import-scan.service \
 	%D%/systemd/system/zfs-import.target \
 	%D%/systemd/system/zfs-mount.service \
+	%D%/systemd/system/[email protected] \
 	%D%/systemd/system/[email protected] \
 	%D%/systemd/system/[email protected] \
 	%D%/systemd/system/[email protected] \

etc/systemd/system/[email protected]

@@ -0,0 +1,26 @@
+[Unit]
+Description=Mount ZFS filesystem %I
+Documentation=man:zfs(8)
+DefaultDependencies=no
+After=systemd-udev-settle.service
+After=zfs-import.target
+After=zfs-mount.service
+After=systemd-remount-fs.service
+Before=local-fs.target
+ConditionPathIsDirectory=/sys/module/zfs
+
+# This merely tells the service manager
+# that unmounting everything undoes the
+# effect of this service. No extra logic
+# is ran as a result of these settings.
+Conflicts=umount.target
+Before=umount.target
+
+[Service]
+Type=oneshot
+RemainAfterExit=yes
+EnvironmentFile=-@initconfdir@/zfs
+ExecStart=@sbindir@/zfs mount -R %I
+
+[Install]
+WantedBy=zfs.target

rpm/generic/zfs.spec.in

@@ -388,7 +388,7 @@ support for unlocking datasets on user login.
 
 %if 0%{?_systemd}
     %define systemd --enable-systemd --with-systemdunitdir=%{_unitdir} --with-systemdpresetdir=%{_presetdir} --with-systemdmodulesloaddir=%{_modulesloaddir} --with-systemdgeneratordir=%{_systemdgeneratordir} --disable-sysvinit
-    %define systemd_svcs zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-share.service zfs-zed.service zfs.target zfs-import.target zfs-volume-wait.service zfs-volumes.target
+    %define systemd_svcs zfs-import-cache.service zfs-import-scan.service zfs-mount.service zfs-[email protected] zfs-share.service zfs-zed.service zfs.target zfs-import.target zfs-volume-wait.service zfs-volumes.target
 %else
     %define systemd --enable-sysvinit --disable-systemd
 %endif