Quoting Oren Laadan (orenl-eQaUEPhvms7ENvBUuze7eA@public.gmane.org):

+/**
+ * cr_fill_fname - return pathname of a given file
+ * @path: path name
+ * @root: relative root
+ * @buf: buffer for pathname
+ * @n: buffer length (in) and pathname length (out)
+ */
+static char *
+cr_fill_fname(struct path *path, struct path *root, char *buf, int *n)
+{
+	struct path tmp = *root;
+	char *fname;
+
+	BUG_ON(!buf);
+	fname = __d_path(path, &tmp, buf, *n);
+	if (!IS_ERR(fname))
+		*n = (buf + (*n) - fname);
+	/*
+	 * FIXME: if __d_path() changed these, it must have stepped out of
+	 * init's namespace. Since currently we require a unified namespace
+	 * within the container: simply fail.
+	 */
+	if (tmp.mnt != root->mnt || tmp.dentry != root->dentry)
+		fname = ERR_PTR(-EBADF);
+
+	return fname;
+}

You still are not taking the dcache_lock around __d_path.

-serge
--
To unsubscribe from this list: send the line "unsubscribe linux-api" in
the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html