3 files changed, 41 insertions, 2 deletions
diff --git a/pkg/sentry/fsimpl/overlay/overlay.go b/pkg/sentry/fsimpl/overlay/overlay.go
index f28411b5b..6fe97c57b 100644
--- a/pkg/sentry/fsimpl/overlay/overlay.go
+++ b/pkg/sentry/fsimpl/overlay/overlay.go
@@ -33,12 +33,14 @@
 package overlay
 
 import (
+	"fmt"
 	"strings"
 	"sync/atomic"
 
 	"gvisor.dev/gvisor/pkg/abi/linux"
 	"gvisor.dev/gvisor/pkg/context"
 	"gvisor.dev/gvisor/pkg/fspath"
+	"gvisor.dev/gvisor/pkg/refsvfs2"
 	fslock "gvisor.dev/gvisor/pkg/sentry/fs/lock"
 	"gvisor.dev/gvisor/pkg/sentry/kernel/auth"
 	"gvisor.dev/gvisor/pkg/sentry/memmap"
@@ -484,6 +486,9 @@ func (fs *filesystem) newDentry() *dentry {
 	}
 	d.lowerVDs = d.inlineLowerVDs[:0]
 	d.vfsd.Init(d)
+	if refsvfs2.LeakCheckEnabled() {
+		refsvfs2.Register(d, "overlay.dentry")
+	}
 	return d
 }
 
@@ -583,6 +588,14 @@ func (d *dentry) destroyLocked(ctx context.Context) {
 			panic("overlay.dentry.DecRef() called without holding a reference")
 		}
 	}
+	if refsvfs2.LeakCheckEnabled() {
+		refsvfs2.Unregister(d, "overlay.dentry")
+	}
+}
+
+// LeakMessage implements refsvfs2.CheckedObject.LeakMessage.
+func (d *dentry) LeakMessage() string {
+	return fmt.Sprintf("[overlay.dentry %p] reference count of %d instead of -1", d, atomic.LoadInt64(&d.refs))
 }
 
 // InotifyWithParent implements vfs.DentryImpl.InotifyWithParent.
diff --git a/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
index bdab5d0be..760300f42 100644
--- a/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
+++ b/pkg/sentry/fsimpl/overlay/overlay_state_autogen.go
@@ -183,8 +183,6 @@ func (d *dentry) StateSave(stateSinkObject state.Sink) {
 	stateSinkObject.Save(21, &d.watches)
 }
 
-func (d *dentry) afterLoad() {}
-
 func (d *dentry) StateLoad(stateSourceObject state.Source) {
 	stateSourceObject.Load(0, &d.vfsd)
 	stateSourceObject.Load(1, &d.refs)
@@ -208,6 +206,7 @@ func (d *dentry) StateLoad(stateSourceObject state.Source) {
 	stateSourceObject.Load(19, &d.isMappable)
 	stateSourceObject.Load(20, &d.locks)
 	stateSourceObject.Load(21, &d.watches)
+	stateSourceObject.AfterLoad(d.afterLoad)
 }
 
 func (fd *fileDescription) StateTypeName() string {
diff --git a/pkg/sentry/fsimpl/overlay/save_restore.go b/pkg/sentry/fsimpl/overlay/save_restore.go
new file mode 100644
index 000000000..054e17b17
--- /dev/null
+++ b/pkg/sentry/fsimpl/overlay/save_restore.go
@@ -0,0 +1,27 @@
+// Copyright 2020 The gVisor Authors.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package overlay
+
+import (
+	"sync/atomic"
+
+	"gvisor.dev/gvisor/pkg/refsvfs2"
+)
+
+func (d *dentry) afterLoad() {
+	if refsvfs2.LeakCheckEnabled() && atomic.LoadInt64(&d.refs) != -1 {
+		refsvfs2.Register(d, "overlay.dentry")
+	}
+}