Add vfs.Dentry.Children().

PiperOrigin-RevId: 286660774

pkg/sentry/vfs/dentry.go

@@ -85,12 +85,12 @@ type Dentry struct {
 	// mounts is accessed using atomic memory operations.
 	mounts uint32
 
-	// mu synchronizes disowning and mounting over this Dentry.
-	mu sync.Mutex
-
 	// children are child Dentries.
 	children map[string]*Dentry
 
+	// mu synchronizes disowning and mounting over this Dentry.
+	mu sync.Mutex
+
 	// impl is the DentryImpl associated with this Dentry. impl is immutable.
 	// This should be the last field in Dentry.
 	impl DentryImpl
@@ -199,6 +199,18 @@ func (d *Dentry) HasChildren() bool {
 	return len(d.children) != 0
 }
 
+// Children returns a map containing all of d's children.
+func (d *Dentry) Children() map[string]*Dentry {
+	if !d.HasChildren() {
+		return nil
+	}
+	m := make(map[string]*Dentry)
+	for name, child := range d.children {
+		m[name] = child
+	}
+	return m
+}
+
 // InsertChild makes child a child of d with the given name.
 //
 // InsertChild is a mutator of d and child.