struct dentry_operations {
  int (*d_revalidate) (struct dentry *, struct nameidata *);
  int (*d_hash) (struct dentry *, struct qstr *);
  int (*d_compare) (struct dentry *, struct qstr *, struct qstr *);
  int (*d_delete) (struct dentry *);
  void (*d_release) (struct dentry *);
  void (*d_iput) (struct dentry *, struct inode *);
};