MDEV-10235: Deadlock in CREATE TABLE .. AS SELECT .. if result set is empty in Galera

In CTAS, handlers get registered under statement transaction
(st_transactions::stmt), while ha_fake_trx_id(), used by CTAS,
looked under standard transaction (st_transactions::all) for
registered handlers, and thus it failed to grab a fake transaction
ID. As a result, with no valid transaction ID, wsrep commit failed
with an error.

ha_fake_trx_id() now looks for handlers registered under 'stmt'
in case 'all' is empty. Also modified the logic to print warning
only once if none of the registered handlers have fake_trx_id.

mysql-test/suite/galera/r/create.result

@@ -68,4 +68,17 @@ CREATE TABLE `t2` (`c1` INT) ENGINE=INNODB SELECT * FROM t1;
 COMMIT;
 SET autocommit=1;
 DROP TABLE t1, t2;
+#
+# MDEV-10235: Deadlock in CREATE TABLE ... AS SELECT .. if result set
+# is empty in Galera
+#
+CREATE TABLE t1(c1 INT) ENGINE=INNODB;
+INSERT INTO t1 VALUES(1);
+CREATE TABLE t2 AS SELECT * FROM t1 WHERE c1=2;
+SELECT * FROM t1;
+c1
+1
+SELECT * FROM t2;
+c1
+DROP TABLE t1, t2;
 # End of tests

mysql-test/suite/galera/suite.pm

@@ -67,7 +67,6 @@ push @::global_suppressions,
      qr|WSREP: gcs_caused\(\) returned .*|,
      qr|WSREP: Protocol violation. JOIN message sender .* is not in state transfer \(SYNCED\). Message ignored.|,
      qr(WSREP: Action message in non-primary configuration from member [0-9]*),
-     qr(WSREP: cannot get fake InnoDB transaction ID),
    );
 
 

mysql-test/suite/galera/t/create.test

@@ -68,6 +68,22 @@ SET autocommit=1;
 # Cleanup
 DROP TABLE t1, t2;
 
+
+--echo #
+--echo # MDEV-10235: Deadlock in CREATE TABLE ... AS SELECT .. if result set
+--echo # is empty in Galera
+--echo #
+--connection node_1
+CREATE TABLE t1(c1 INT) ENGINE=INNODB;
+INSERT INTO t1 VALUES(1);
+CREATE TABLE t2 AS SELECT * FROM t1 WHERE c1=2;
+
+--connection node_2
+SELECT * FROM t1;
+SELECT * FROM t2;
+# Cleanup
+DROP TABLE t1, t2;
+
 --source include/galera_end.inc
 --echo # End of tests
 

mysql-test/suite/wsrep/r/binlog_format.result

 call mtr.add_suppression("WSREP: MariaDB Galera does not support binlog format.*");
-call mtr.add_suppression("WSREP: cannot get fake InnoDB transaction ID");
+call mtr.add_suppression("WSREP: Cannot get fake transaction ID from storage engine.");
 #
 # MDEV-4227: Galera server should stop crashing on setting binlog_format STATEMENT
 #

mysql-test/suite/wsrep/t/binlog_format.test

@@ -2,7 +2,7 @@
 --source include/have_binlog_format_row.inc
 
 call mtr.add_suppression("WSREP: MariaDB Galera does not support binlog format.*");
-call mtr.add_suppression("WSREP: cannot get fake InnoDB transaction ID");
+call mtr.add_suppression("WSREP: Cannot get fake transaction ID from storage engine.");
 
 --echo #
 --echo # MDEV-4227: Galera server should stop crashing on setting binlog_format STATEMENT

sql/handler.cc

@@ -6104,25 +6104,42 @@ int ha_abort_transaction(THD *bf_thd, THD *victim_thd, my_bool signal)
 void ha_fake_trx_id(THD *thd)
 {
   DBUG_ENTER("ha_fake_trx_id");
+
+  bool no_fake_trx_id= true;
+
   if (!WSREP(thd))
   {
     DBUG_VOID_RETURN;
   }
 
-  THD_TRANS *trans= &thd->transaction.all;
+  /* Try statement transaction if standard one is not set. */
+  THD_TRANS *trans= (thd->transaction.all.ha_list) ?  &thd->transaction.all :
+    &thd->transaction.stmt;
+
   Ha_trx_info *ha_info= trans->ha_list, *ha_info_next;
 
   for (; ha_info; ha_info= ha_info_next)
   {
     handlerton *hton= ha_info->ht();
-    if (!hton->fake_trx_id)
+    if (hton->fake_trx_id)
     {
-      WSREP_WARN("cannot get fake InnoDB transaction ID");
-    }
-    else
       hton->fake_trx_id(hton, thd);
+
+      /* Got a fake trx id. */
+      no_fake_trx_id= false;
+
+      /*
+        We need transaction ID from just one storage engine providing
+        fake_trx_id (which will most likely be the case).
+      */
+      break;
+    }
     ha_info_next= ha_info->next();
   }
+
+  if (unlikely(no_fake_trx_id))
+    WSREP_WARN("Cannot get fake transaction ID from storage engine.");
+
   DBUG_VOID_RETURN;
 }
 #endif /* WITH_WSREP */