cgroup: always honor --cgroup-parent with cgroupfs

if --cgroup-parent is specified, always honor it without doing any
detection whether cgroups are supported or not.

Closes: https://github.com/containers/podman/issues/10173

Signed-off-by: Giuseppe Scrivano <gscrivan@redhat.com>

2 files changed, 13 insertions, 2 deletions

diff --git a/libpod/container_internal_linux.go b/libpod/container_internal_linux.go
index f4762b5ff..f6045f881 100644
--- a/libpod/container_internal_linux.go
+++ b/libpod/container_internal_linux.go
@@ -2224,8 +2224,19 @@ func (c *Container) getOCICgroupPath() (string, error) {
 	}
 	cgroupManager := c.CgroupManager()
 	switch {
-	case (rootless.IsRootless() && (cgroupManager == config.CgroupfsCgroupsManager || !unified)) || c.config.NoCgroups:
+	case c.config.NoCgroups:
 		return "", nil
+	case (rootless.IsRootless() && (cgroupManager == config.CgroupfsCgroupsManager || !unified)):
+		if c.config.CgroupParent == CgroupfsDefaultCgroupParent {
+			// old versions of podman were setting the CgroupParent to CgroupfsDefaultCgroupParent
+			// by default.  Avoid breaking these versions and check whether the cgroup parent is
+			// set to the default and in this case enable the old behavior.  It should not be a real
+			// problem because the default CgroupParent is usually owned by root so rootless users
+			// cannot access it.
+			// This check might be lifted in a future version of Podman.
+			return "", nil
+		}
+		return c.config.CgroupParent, nil
 	case c.config.CgroupsMode == cgroupSplit:
 		if c.config.CgroupParent != "" {
 			return c.config.CgroupParent, nil
diff --git a/libpod/runtime_ctr.go b/libpod/runtime_ctr.go
index 0acf88cbc..328f47c12 100644
--- a/libpod/runtime_ctr.go
+++ b/libpod/runtime_ctr.go
@@ -296,7 +296,7 @@ func (r *Runtime) setupContainer(ctx context.Context, ctr *Container) (_ *Contai
 						return nil, errors.Wrapf(define.ErrInternal, "pod %s cgroup is not set", pod.ID())
 					}
 					ctr.config.CgroupParent = podCgroup
-				} else {
+				} else if !rootless.IsRootless() {
 					ctr.config.CgroupParent = CgroupfsDefaultCgroupParent
 				}
 			} else if strings.HasSuffix(path.Base(ctr.config.CgroupParent), ".slice") {