+int dentry_needs_remove_privs(struct user_namespace *, struct dentry *dentry);
+bool in_group_or_capable(struct user_namespace *mnt_userns,
+ const struct inode *inode, vfsgid_t vfsgid);
+void lock_two_inodes(struct inode *inode1, struct inode *inode2,
+ unsigned subclass1, unsigned subclass2);