chdir(2): unspaghettify a bit...

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

Author: Al Viro

fs/open.c

@@ -558,26 +558,19 @@ SYSCALL_DEFINE1(chdir, const char __user *, filename)
 	struct path path;
 	int error;
 	unsigned int lookup_flags = LOOKUP_FOLLOW | LOOKUP_DIRECTORY;
-	struct filename *name = getname(filename);
+	CLASS(filename, name)(filename);
 retry:
 	error = filename_lookup(AT_FDCWD, name, lookup_flags, &path, NULL);
-	if (error)
-		goto out;
-
-	error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
-	if (error)
-		goto dput_and_out;
-
-	set_fs_pwd(current->fs, &path);
-
-dput_and_out:
-	path_put(&path);
-	if (retry_estale(error, lookup_flags)) {
-		lookup_flags |= LOOKUP_REVAL;
-		goto retry;
+	if (!error) {
+		error = path_permission(&path, MAY_EXEC | MAY_CHDIR);
+		if (!error)
+			set_fs_pwd(current->fs, &path);
+		path_put(&path);
+		if (retry_estale(error, lookup_flags)) {
+			lookup_flags |= LOOKUP_REVAL;
+			goto retry;
+		}
 	}
-out:
-	putname(name);
 	return error;
 }