rem: rootfs_rewind_dir(fs_cookie _fs, fs_vnode _vnode, file_cookie _cookie)
add: rootfs_rewind_dir(fs_volume _fs, fs_vnode _vnode, fs_cookie _cookie)
context: rootfs_rewind_dir(fs_cookie _fs, fs_vnode _vnode, file_cookie _cookie){	struct rootfs *fs = _fs;	struct rootfs_vnode *vnode = _vnode;	struct rootfs_cookie *cookie = _cookie;	mutex_lock(&fs->lock);	cookie->ptr = vnode->stream.dir.dir_head;	mutex_unlock(&fs->lock);	return B_OK;}