2 files changed, 7 insertions, 10 deletions
diff --git a/pkg/sentry/fsimpl/cgroupfs/base.go b/pkg/sentry/fsimpl/cgroupfs/base.go
index 0f54888d8..6512e9cdb 100644
--- a/pkg/sentry/fsimpl/cgroupfs/base.go
+++ b/pkg/sentry/fsimpl/cgroupfs/base.go
@@ -26,7 +26,6 @@ import (
 	"gvisor.dev/gvisor/pkg/sentry/fsimpl/kernfs"
 	"gvisor.dev/gvisor/pkg/sentry/kernel"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
-	"gvisor.dev/gvisor/pkg/sentry/vfs"
 	"gvisor.dev/gvisor/pkg/syserror"
 	"gvisor.dev/gvisor/pkg/usermem"
 )
@@ -68,11 +67,6 @@ func (c *controllerCommon) Enabled() bool {
 	return true
 }
 
-// Filesystem implements kernel.CgroupController.Filesystem.
-func (c *controllerCommon) Filesystem() *vfs.Filesystem {
-	return c.fs.VFSFilesystem()
-}
-
 // RootCgroup implements kernel.CgroupController.RootCgroup.
 func (c *controllerCommon) RootCgroup() kernel.Cgroup {
 	return c.fs.rootCgroup()
diff --git a/pkg/sentry/fsimpl/cgroupfs/cgroupfs.go b/pkg/sentry/fsimpl/cgroupfs/cgroupfs.go
index bd3e69757..54050de3c 100644
--- a/pkg/sentry/fsimpl/cgroupfs/cgroupfs.go
+++ b/pkg/sentry/fsimpl/cgroupfs/cgroupfs.go
@@ -109,7 +109,7 @@ type InternalData struct {
 	DefaultControlValues map[string]int64
 }
 
-// filesystem implements vfs.FilesystemImpl.
+// filesystem implements vfs.FilesystemImpl and kernel.cgroupFS.
 //
 // +stateify savable
 type filesystem struct {
@@ -139,6 +139,11 @@ type filesystem struct {
 	tasksMu sync.RWMutex `state:"nosave"`
 }
 
+// InitializeHierarchyID implements kernel.cgroupFS.InitializeHierarchyID.
+func (fs *filesystem) InitializeHierarchyID(hid uint32) {
+	fs.hierarchyID = hid
+}
+
 // Name implements vfs.FilesystemType.Name.
 func (FilesystemType) Name() string {
 	return Name
@@ -284,14 +289,12 @@ func (fsType FilesystemType) GetFilesystem(ctx context.Context, vfsObj *vfs.Virt
 	// Register controllers. The registry may be modified concurrently, so if we
 	// get an error, we raced with someone else who registered the same
 	// controllers first.
-	hid, err := r.Register(fs.kcontrollers)
-	if err != nil {
+	if err := r.Register(fs.kcontrollers, fs); err != nil {
 		ctx.Infof("cgroupfs.FilesystemType.GetFilesystem: failed to register new hierarchy with controllers %v: %v", wantControllers, err)
 		rootD.DecRef(ctx)
 		fs.VFSFilesystem().DecRef(ctx)
 		return nil, nil, syserror.EBUSY
 	}
-	fs.hierarchyID = hid
 
 	// Move all existing tasks to the root of the new hierarchy.
 	k.PopulateNewCgroupHierarchy(fs.rootCgroup())