Re: [PATCH v2 4/7] reftable/stack: stop using `fsync_component()` directly

> @@ -43,17 +42,28 @@ static int stack_filename(struct reftable_buf *dest, struct reftable_stack *st,
>  	return 0;
>  }
>
> -static ssize_t reftable_fd_write(void *arg, const void *data, size_t sz)
> +static int stack_fsync(const struct reftable_write_options *opts, int fd)
>  {
> -	int *fdp = (int *)arg;
> -	return write_in_full(*fdp, data, sz);
> +	if (opts->fsync)
> +		return opts->fsync(fd);
> +	return fsync(fd);
>  }
>
> -static int reftable_fd_flush(void *arg)
> +struct fd_writer {
> +	const struct reftable_write_options *opts;
> +	int fd;
> +};
> +
> +static ssize_t fd_writer_write(void *arg, const void *data, size_t sz)
>  {
> -	int *fdp = (int *)arg;
> +	struct fd_writer *writer = arg;
> +	return write_in_full(writer->fd, data, sz);