diff --git a/file_system.go b/file_system.go
index fc1cd49..083902c 100644
--- a/file_system.go
+++ b/file_system.go
@@ -197,36 +197,10 @@ type HandleID uint64
 // ReadDirRequest.Offset for details.
 type DirOffset uint64
 
-////////////////////////////////////////////////////////////////////////
-// Requests and responses
-////////////////////////////////////////////////////////////////////////
-
-type InitRequest struct {
-	// User and group IDs for the process that is mounting the file system.
-	Uid uint32
-	Gid uint32
-}
-
-type InitResponse struct {
-}
-
-type LookUpInodeRequest struct {
-	// The ID of the directory inode to which the child belongs.
-	Parent InodeID
-
-	// The name of the child of interest, relative to the parent. For example, in
-	// this directory structure:
-	//
-	//     foo/
-	//         bar/
-	//             baz
-	//
-	// the file system may receive a request to look up the child named "bar" for
-	// the parent foo/.
-	Name string
-}
-
-type LookUpInodeResponse struct {
+// Information about a child inode within its parent directory. Shared by the
+// responses for LookUpInode, MkDir, etc. Consumed by the kernel in order to
+// set up a dcache entry.
+type ChildInodeEntry struct {
 	// The ID of the child inode. The file system must ensure that the returned
 	// inode ID remains valid until a later call to ForgetInode.
 	Child InodeID
@@ -294,6 +268,39 @@ type LookUpInodeResponse struct {
 	EntryExpiration time.Time
 }
 
+////////////////////////////////////////////////////////////////////////
+// Requests and responses
+////////////////////////////////////////////////////////////////////////
+
+type InitRequest struct {
+	// User and group IDs for the process that is mounting the file system.
+	Uid uint32
+	Gid uint32
+}
+
+type InitResponse struct {
+}
+
+type LookUpInodeRequest struct {
+	// The ID of the directory inode to which the child belongs.
+	Parent InodeID
+
+	// The name of the child of interest, relative to the parent. For example, in
+	// this directory structure:
+	//
+	//     foo/
+	//         bar/
+	//             baz
+	//
+	// the file system may receive a request to look up the child named "bar" for
+	// the parent foo/.
+	Name string
+}
+
+type LookUpInodeResponse struct {
+	Entry ChildInodeEntry
+}
+
 type GetInodeAttributesRequest struct {
 	// The inode of interest.
 	Inode InodeID
@@ -326,7 +333,7 @@ type MkDirRequest struct {
 }
 
 type MkDirResponse struct {
-	// TODO(jacobsa): Create a structure and share it with LookUpInodeResponse.
+	Entry ChildInodeEntry
 }
 
 type OpenDirRequest struct {
diff --git a/samples/memfs/fs.go b/samples/memfs/fs.go
index f78d5c9..df164ca 100644
--- a/samples/memfs/fs.go
+++ b/samples/memfs/fs.go
@@ -151,12 +151,12 @@ func (fs *memFS) LookUpInode(
 	defer child.mu.RUnlock()
 
 	// Fill in the response.
-	resp.Attributes = child.attributes
+	resp.Entry.Attributes = child.attributes
 
 	// We don't spontaneously mutate, so the kernel can cache as long as it wants
 	// (since it also handles invalidation).
-	resp.AttributesExpiration = fs.clock.Now().Add(365 * 24 * time.Hour)
-	resp.EntryExpiration = resp.EntryExpiration
+	resp.Entry.AttributesExpiration = fs.clock.Now().Add(365 * 24 * time.Hour)
+	resp.Entry.EntryExpiration = resp.Entry.EntryExpiration
 
 	return
 }
diff --git a/server.go b/server.go
index 5b321f1..4690a95 100644
--- a/server.go
+++ b/server.go
@@ -112,12 +112,13 @@ func (s *server) handleFuseRequest(fuseReq bazilfuse.Request) {
 		}
 
 		// Convert the response.
+		e := &resp.Entry
 		fuseResp := &bazilfuse.LookupResponse{
-			Node:       bazilfuse.NodeID(resp.Child),
-			Generation: uint64(resp.Generation),
-			Attr:       convertAttributes(resp.Child, resp.Attributes),
-			AttrValid:  resp.AttributesExpiration.Sub(s.clock.Now()),
-			EntryValid: resp.EntryExpiration.Sub(s.clock.Now()),
+			Node:       bazilfuse.NodeID(e.Child),
+			Generation: uint64(e.Generation),
+			Attr:       convertAttributes(e.Child, e.Attributes),
+			AttrValid:  e.AttributesExpiration.Sub(s.clock.Now()),
+			EntryValid: e.EntryExpiration.Sub(s.clock.Now()),
 		}
 
 		s.logger.Print("Responding:", fuseResp)