From c6e8cb79260cdfc435ceecc797efb92cc5977632 Mon Sep 17 00:00:00 2001
From: Kir Kolyshkin <kolyshkin@gmail.com>
Date: Thu, 23 Mar 2023 10:56:20 -0700
Subject: [PATCH] libct/cg/sd: refactor startUnit

Move error handling earlier, removing "if err == nil" block.

No change of logic.

Signed-off-by: Kir Kolyshkin <kolyshkin@gmail.com>
---
 libcontainer/cgroups/systemd/common.go | 37 ++++++++++++++------------
 1 file changed, 20 insertions(+), 17 deletions(-)

diff --git a/libcontainer/cgroups/systemd/common.go b/libcontainer/cgroups/systemd/common.go
index 2f0767b2f..c0a058012 100644
--- a/libcontainer/cgroups/systemd/common.go
+++ b/libcontainer/cgroups/systemd/common.go
@@ -130,24 +130,27 @@ func startUnit(cm *dbusConnManager, unitName string, properties []systemdDbus.Pr
 		_, err := c.StartTransientUnitContext(context.TODO(), unitName, "replace", properties, statusChan)
 		return err
 	})
-	if err == nil {
-		timeout := time.NewTimer(30 * time.Second)
-		defer timeout.Stop()
-
-		select {
-		case s := <-statusChan:
-			close(statusChan)
-			// Please refer to https://pkg.go.dev/github.com/coreos/go-systemd/v22/dbus#Conn.StartUnit
-			if s != "done" {
-				resetFailedUnit(cm, unitName)
-				return fmt.Errorf("error creating systemd unit `%s`: got `%s`", unitName, s)
-			}
-		case <-timeout.C:
-			resetFailedUnit(cm, unitName)
-			return errors.New("Timeout waiting for systemd to create " + unitName)
+	if err != nil {
+		if !isUnitExists(err) {
+			return err
 		}
-	} else if !isUnitExists(err) {
-		return err
+		return nil
+	}
+
+	timeout := time.NewTimer(30 * time.Second)
+	defer timeout.Stop()
+
+	select {
+	case s := <-statusChan:
+		close(statusChan)
+		// Please refer to https://pkg.go.dev/github.com/coreos/go-systemd/v22/dbus#Conn.StartUnit
+		if s != "done" {
+			resetFailedUnit(cm, unitName)
+			return fmt.Errorf("error creating systemd unit `%s`: got `%s`", unitName, s)
+		}
+	case <-timeout.C:
+		resetFailedUnit(cm, unitName)
+		return errors.New("Timeout waiting for systemd to create " + unitName)
 	}
 
 	return nil