+/* requires cl_lock: */
+static struct nfsd4_conn * __nfsd4_find_backchannel(struct nfs4_client *clp)
+{
+ struct nfsd4_session *s;
+ struct nfsd4_conn *c;
+
+ list_for_each_entry(s, &clp->cl_sessions, se_perclnt) {
+ list_for_each_entry(c, &s->se_conns, cn_persession) {
+ if (c->cn_flags & NFS4_CDFC4_BACK)
+ return c;
+ }
+ }
+ return NULL;
+}
+
+static void nfsd4_process_cb_update(struct nfsd4_callback *cb)