Declared a MkDir method.

file_system.go

@@ -52,6 +52,16 @@ type FileSystem interface {
 		ctx context.Context,
 		req *ForgetInodeRequest) (*ForgetInodeResponse, error)
 
+	///////////////////////////////////
+	// Inode creation
+	///////////////////////////////////
+
+	// Create a directory inode as a child of an existing directory inode. The
+	// kernel sends this in response to a mkdir(2) call.
+	MkDir(
+		ctx context.Context,
+		req *MkDirRequest) (*MkDirResponse, error)
+
 	///////////////////////////////////
 	// Directory handles
 	///////////////////////////////////
@@ -306,6 +316,19 @@ type ForgetInodeRequest struct {
 type ForgetInodeResponse struct {
 }
 
+type MkDirRequest struct {
+	// The ID of parent directory inode within which to create the child.
+	Parent InodeID
+
+	// The name of the child to create, and the mode with which to create it.
+	Name string
+	Mode os.FileMode
+}
+
+type MkDirResponse struct {
+	// TODO(jacobsa): Create a structure and share it with LookUpInodeResponse.
+}
+
 type OpenDirRequest struct {
 	// The ID of the inode to be opened.
 	Inode InodeID

fuseutil/not_implemented_file_system.go

@@ -40,6 +40,12 @@ func (fs *NotImplementedFileSystem) ForgetInode(
 	return nil, fuse.ENOSYS
 }
 
+func (fs *NotImplementedFileSystem) MkDir(
+	ctx context.Context,
+	req *fuse.MkDirRequest) (*fuse.MkDirResponse, error) {
+	return nil, fuse.ENOSYS
+}
+
 func (fs *NotImplementedFileSystem) OpenDir(
 	ctx context.Context,
 	req *fuse.OpenDirRequest) (*fuse.OpenDirResponse, error) {