cgroup: change cgroup deletion logic on v1

do not raise an error if the cgroup exists at least on one
controller.

Previously it expected the cgroup to exists under all the
controllers.

[NO TESTS NEEDED]

Closes: containers#9252

Signed-off-by: Giuseppe Scrivano <[email protected]>

pkg/cgroups/cgroups.go

@@ -331,18 +331,24 @@ func Load(path string) (*CgroupControl, error) {
 		control.additionalControllers = controllers
 	}
 	if !cgroup2 {
+		oneExists := false
+		// check that the cgroup exists at least under one controller
 		for name := range handlers {
 			p := control.getCgroupv1Path(name)
-			if _, err := os.Stat(p); err != nil {
-				if os.IsNotExist(err) {
-					if rootless.IsRootless() {
-						return nil, ErrCgroupV1Rootless
-					}
-					// compatible with the error code
-					// used by containerd/cgroups
-					return nil, ErrCgroupDeleted
-				}
+			if _, err := os.Stat(p); err == nil {
+				oneExists = true
+				break
+			}
+		}
+
+		// if there is no controller at all, raise an error
+		if !oneExists {
+			if rootless.IsRootless() {
+				return nil, ErrCgroupV1Rootless
 			}
+			// compatible with the error code
+			// used by containerd/cgroups
+			return nil, ErrCgroupDeleted
 		}
 	}
 	return control, nil