relay doesn't reference the pages it adds, however we need a non-NULL
hook or splice_to_pipe() can oops.
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>
        .get = generic_pipe_buf_get,
 };
 
+static void relay_page_release(struct splice_pipe_desc *spd, unsigned int i)
+{
+}
+
 /*
  *     subbuf_splice_actor - splice up to one subbuf's worth of data
  */
                .partial = partial,
                .flags = flags,
                .ops = &relay_pipe_buf_ops,
+               .spd_release = relay_page_release,
        };
 
        if (rbuf->subbufs_produced == rbuf->subbufs_consumed)