extern struct dentry *lookup_one_len(const char *, struct dentry *, int);
extern struct dentry *lookup_one_len_unlocked(const char *, struct dentry *, int);
extern struct dentry *lookup_positive_unlocked(const char *, struct dentry *, int);
+struct dentry *lookup_one(struct user_namespace *, const char *, struct dentry *, int);
extern int follow_down_one(struct path *);
extern int follow_down(struct path *);