init: add an init_utimes helper

Add a simple helper to set timestamps with a kernel space file name and
switch the early init code over to it.
Signed-off-by: Christoph Hellwig <hch@lst.de>

fs/init.c

@@ -238,3 +238,16 @@ int __init init_rmdir(const char *pathname)
 {
 	return do_rmdir(AT_FDCWD, getname_kernel(pathname));
 }
+
+int __init init_utimes(char *filename, struct timespec64 *ts)
+{
+	struct path path;
+	int error;
+
+	error = kern_path(filename, 0, &path);
+	if (error)
+		return error;
+	error = vfs_utimes(&path, ts);
+	path_put(&path);
+	return error;
+}

include/linux/init_syscalls.h

@@ -15,3 +15,4 @@ int __init init_symlink(const char *oldname, const char *newname);
 int __init init_unlink(const char *pathname);
 int __init init_mkdir(const char *pathname, umode_t mode);
 int __init init_rmdir(const char *pathname);
+int __init init_utimes(char *filename, struct timespec64 *ts);

init/initramfs.c

@@ -111,8 +111,7 @@ static long __init do_utime(char *filename, time64_t mtime)
 	t[0].tv_nsec = 0;
 	t[1].tv_sec = mtime;
 	t[1].tv_nsec = 0;
-
-	return do_utimes(AT_FDCWD, filename, t, AT_SYMLINK_NOFOLLOW);
+	return init_utimes(filename, t);
 }
 
 static __initdata LIST_HEAD(dir_list);