migration: Allow migrate_fd_connect to take an Error *

Allow whatever is performing the connection to pass migrate_fd_connect
an error to indicate there was a problem during connection, an allow
us to clean up.

The caller must free the error.

Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>
Reviewed-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Juan Quintela <quintela@redhat.com>
Signed-off-by: Dr. David Alan Gilbert <dgilbert@redhat.com>

migration/channel.c

@@ -78,6 +78,6 @@ void migration_channel_connect(MigrationState *s,
 
         s->to_dst_file = f;
 
-        migrate_fd_connect(s);
+        migrate_fd_connect(s, NULL);
     }
 }

migration/migration.c

@@ -2378,10 +2378,15 @@ static void *migration_thread(void *opaque)
     return NULL;
 }
 
-void migrate_fd_connect(MigrationState *s)
+void migrate_fd_connect(MigrationState *s, Error *error_in)
 {
     s->expected_downtime = s->parameters.downtime_limit;
     s->cleanup_bh = qemu_bh_new(migrate_fd_cleanup, s);
+    if (error_in) {
+        migrate_fd_error(s, error_in);
+        migrate_fd_cleanup(s);
+        return;
+    }
 
     qemu_file_set_blocking(s->to_dst_file, true);
     qemu_file_set_rate_limit(s->to_dst_file,

migration/migration.h

@@ -190,7 +190,7 @@ uint64_t migrate_max_downtime(void);
 void migrate_set_error(MigrationState *s, const Error *error);
 void migrate_fd_error(MigrationState *s, const Error *error);
 
-void migrate_fd_connect(MigrationState *s);
+void migrate_fd_connect(MigrationState *s, Error *error_in);
 
 MigrationState *migrate_init(void);
 bool migration_is_blocked(Error **errp);

migration/rdma.c

@@ -3758,7 +3758,7 @@ void rdma_start_outgoing_migration(void *opaque,
     trace_rdma_start_outgoing_migration_after_rdma_connect();
 
     s->to_dst_file = qemu_fopen_rdma(rdma, "wb");
-    migrate_fd_connect(s);
+    migrate_fd_connect(s, NULL);
     return;
 err:
     g_free(rdma);