mapped_fsuid
mapped_fsuid(req->r_mnt_idmap,
fsuid = no_idmap ? current_fsuid() : mapped_fsuid(idmap, fc->user_ns);
uid = mapped_fsuid(args->idmap, i_user_ns(dir));
inode->i_uid = mapped_fsuid(idmap, i_user_ns(inode));
kuid = mapped_fsuid(idmap, fs_userns);