[RFC PATCH 4/5] migration/socket: Close the listener at the end

["Dr. David Alan Gilbert (git)" <dgilbert@redhat.com>]

From: "Dr. David Alan Gilbert" <dgilbert@redhat.com>

Delay closing the listener until the cleanup hook at the end; mptcp
needs the listener to stay open while the other paths come in.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
---
 migration/multifd.c |  5 +++++
 migration/socket.c  | 24 ++++++++++++++++++------
 2 files changed, 23 insertions(+), 6 deletions(-)

diff --git a/migration/multifd.c b/migration/multifd.c
index a6677c45c8..cebd9029b9 100644
--- a/migration/multifd.c
+++ b/migration/multifd.c
@@ -1165,6 +1165,11 @@ bool multifd_recv_all_channels_created(void)
         return true;
     }
 
+    if (!multifd_recv_state) {
+        /* Called before any connections created */
+        return false;
+    }
+
     return thread_count == qatomic_read(&multifd_recv_state->count);
 }
 
diff --git a/migration/socket.c b/migration/socket.c
index 6016642e04..05705a32d8 100644
--- a/migration/socket.c
+++ b/migration/socket.c
@@ -126,22 +126,31 @@ static void socket_accept_incoming_migration(QIONetListener *listener,
 {
     trace_migration_socket_incoming_accepted();
 
-    qio_channel_set_name(QIO_CHANNEL(cioc), "migration-socket-incoming");
-    migration_channel_process_incoming(QIO_CHANNEL(cioc));
-
     if (migration_has_all_channels()) {
-        /* Close listening socket as its no longer needed */
-        qio_net_listener_disconnect(listener);
-        object_unref(OBJECT(listener));
+        error_report("%s: Extra incoming migration connection; ignoring",
+                     __func__);
+        return;
     }
+
+    qio_channel_set_name(QIO_CHANNEL(cioc), "migration-socket-incoming");
+    migration_channel_process_incoming(QIO_CHANNEL(cioc));
 }
 
+static void
+socket_incoming_migration_end(void *opaque)
+{
+    QIONetListener *listener = opaque;
+
+    qio_net_listener_disconnect(listener);
+    object_unref(OBJECT(listener));
+}
 
 static void
 socket_start_incoming_migration_internal(SocketAddress *saddr,
                                          Error **errp)
 {
     QIONetListener *listener = qio_net_listener_new();
+    MigrationIncomingState *mis = migration_incoming_get_current();
     size_t i;
     int num = 1;
 
@@ -156,6 +165,9 @@ socket_start_incoming_migration_internal(SocketAddress *saddr,
         return;
     }
 
+    mis->transport_data = listener;
+    mis->transport_cleanup = socket_incoming_migration_end;
+
     qio_net_listener_set_client_func_full(listener,
                                           socket_accept_incoming_migration,
                                           NULL, NULL,
-- 
2.31.1