switch-to-configuration: Stop units in one call to systemctl

modules/system/activation/switch-to-configuration.pl

@@ -65,27 +65,30 @@ sub getActiveUnits {
 # Stop all services that no longer exist or have changed in the new
 # configuration.
 # FIXME: handle template units (e.g. getty@.service).
+my @unitsToStop;
 my $active = getActiveUnits;
-foreach my $unitFile (glob "/etc/systemd/system/*") {
-    next unless -f "$unitFile";
-    my $unit = basename $unitFile;
+while (my ($unit, $state) = each %{$active}) {
     my $state = $active->{$unit};
-    if (defined $state && ($state->{state} eq "active" || $state->{state} eq "activating")) {
+    my $curUnitFile = "/etc/systemd/system/$unit";
+    if (-e $curUnitFile && ($state->{state} eq "active" || $state->{state} eq "activating")) {
         my $newUnitFile = "@out@/etc/systemd/system/$unit";
         if (! -e $newUnitFile) {
             print STDERR "stopping obsolete unit ‘$unit’...\n";
-            system("@systemd@/bin/systemctl", "stop", $unit); # FIXME: ignore errors?
-        } elsif (abs_path($unitFile) ne abs_path($newUnitFile)) {
+            push @unitsToStop, $unit;
+        } elsif (abs_path($curUnitFile) ne abs_path($newUnitFile)) {
             print STDERR "stopping changed unit ‘$unit’...\n";
             # Record that this unit needs to be started below.  We
             # write this to a file to ensure that the service gets
             # restarted if we're interrupted.
             write_file($restartListFile, { append => 1 }, "$unit\n");
-            system("@systemd@/bin/systemctl", "stop", $unit); # FIXME: ignore errors?
+            push @unitsToStop, $unit;
         }
     }
 }
 
+system("@systemd@/bin/systemctl", "stop", @unitsToStop)
+    if scalar @unitsToStop > 0; # FIXME: ignore errors?
+
 # Activate the new configuration (i.e., update /etc, make accounts,
 # and so on).
 my $res = 0;
@@ -107,7 +110,7 @@ sub getActiveUnits {
 # manually started).
 my @stopped = split '\n', read_file($restartListFile, err_mode => 'quiet') // "";
 if (scalar @stopped > 0) {
-    print STDERR "restarting unit(s) ", join(" ", @stopped), "...\n";
+    print STDERR "restarting the following units: ", join(" ", @stopped), "\n";
     my %unique = map { $_, 1 } @stopped;
     system("@systemd@/bin/systemctl", "start", keys(%unique)) == 0 or $res = 4;
     unlink($restartListFile);