nfsd4: callback program number is per-session

The callback program is allowed to depend on the session which the
callback is going over.

No change in behavior yet, while we still only do callbacks over a
single session for the lifetime of the client.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index c470cb7..59bc001 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -760,6 +760,7 @@
 
 	new->se_cb_seq_nr = 1;
 	new->se_flags = cses->flags;
+	new->se_cb_prog = cses->callback_prog;
 	kref_init(&new->se_ref);
 	idx = hash_sessionid(&new->se_sessionid);
 	spin_lock(&client_lock);
@@ -782,7 +783,6 @@
 		rpc_copy_addr((struct sockaddr *)&clp->cl_cb_conn.cb_addr, sa);
 		clp->cl_cb_conn.cb_addrlen = svc_addr_len(sa);
 		clp->cl_cb_conn.cb_minorversion = 1;
-		clp->cl_cb_conn.cb_prog = cses->callback_prog;
 		nfsd4_probe_callback(clp, &clp->cl_cb_conn);
 	}
 	return new;