+ /*
+ * If this is an overlayfs then do as if opening the file so we get
+ * write access on the upper inode, not on the overlay inode. For
+ * non-overlay filesystems d_real() is an identity function.
+ */
+ upperdentry = d_real(path->dentry, NULL, O_WRONLY);
+ error = PTR_ERR(upperdentry);
+ if (IS_ERR(upperdentry))
+ goto mnt_drop_write_and_out;
+
+ error = get_write_access(upperdentry->d_inode);