UG#21405865 - LOG WARNING WHEN A DISABLED STORAGE ENGINE IS SET BY RELATED SYS VAR.

The patch logs a warning when default_storage_engine or
default_tmp_storage_engine is set to a disabled storage engine
specified in the disabled_storage_engines option.

Author: thayumanavar77

mysql-test/r/disabled_storage_engines.result

@@ -1,3 +1,5 @@
+CALL mtr.add_suppression("default_storage_engine is set to a disabled storage engine .*");
+CALL mtr.add_suppression("default_tmp_storage_engine is set to a disabled storage engine .*");
 CREATE TABLE t1(c1 int) ENGINE=HEAP;
 ERROR HY000: Storage engine MEMORY is disabled (Table creation is disallowed).
 CREATE TABLE t1 (c1 int) ENGINE=MYISAM;
@@ -60,6 +62,8 @@ INSTALL PLUGIN example SONAME 'ha_example.so';
 CREATE TABLE t1(a int) ENGINE=EXAMPLE;
 ERROR HY000: Storage engine EXAMPLE is disabled (Table creation is disallowed).
 UNINSTALL PLUGIN example;
+SET default_storage_engine=MyISAM;
+SET default_tmp_storage_engine=MyISAM;
 CREATE TABLE t1(a int) ENGINE=MYISAM;
 DROP TABLE t1;
 # restart

mysql-test/t/disabled_storage_engines.test

@@ -11,6 +11,10 @@
 --source include/have_example_plugin.inc
 --source include/not_embedded.inc
 
+CALL mtr.add_suppression("default_storage_engine is set to a disabled storage engine .*");
+CALL mtr.add_suppression("default_tmp_storage_engine is set to a disabled storage engine .*");
+
+
 --ERROR ER_DISABLED_STORAGE_ENGINE
 CREATE TABLE t1(c1 int) ENGINE=HEAP;
 
@@ -110,6 +114,9 @@ eval INSTALL PLUGIN example SONAME '$EXAMPLE_PLUGIN';
 CREATE TABLE t1(a int) ENGINE=EXAMPLE;
 UNINSTALL PLUGIN example;
 
+SET default_storage_engine=MyISAM;
+SET default_tmp_storage_engine=MyISAM;
+
 --exec echo "wait" > $MYSQLTEST_VARDIR/tmp/mysqld.1.expect
 --shutdown_server
 --source include/wait_until_disconnected.inc

sql/handler.cc

@@ -549,11 +549,7 @@ bool ha_is_storage_engine_disabled(handlerton *se_handle)
     se_name.append(",");
     boost::algorithm::to_upper(se_name);
     if(strstr(normalized_se_str.c_str(), se_name.c_str()))
-    {
-      my_error(ER_DISABLED_STORAGE_ENGINE, MYF(0),
-               ha_resolve_storage_engine_name(se_handle));
       return true;
-    }
   }
   return false;
 }

sql/mysqld.cc

@@ -4192,6 +4192,22 @@ a file name for --log-bin-index option", opt_binlog_index_name);
   {
     std::string disabled_se_str(opt_disabled_storage_engines);
     ha_set_normalized_disabled_se_str(disabled_se_str);
+
+    // Log warning if default_storage_engine is a disabled storage engine.
+    handlerton *default_se_handle=
+      plugin_data<handlerton*>(global_system_variables.table_plugin);
+    if (ha_is_storage_engine_disabled(default_se_handle))
+      sql_print_warning("default_storage_engine is set to a "
+                        "disabled storage engine %s.", default_storage_engine);
+
+    // Log warning if default_tmp_storage_engine is a disabled storage engine.
+    handlerton *default_tmp_se_handle=
+      plugin_data<handlerton*>(global_system_variables.temp_table_plugin);
+    if (ha_is_storage_engine_disabled(default_tmp_se_handle))
+      sql_print_warning("default_tmp_storage_engine is set to a "
+                        "disabled storage engine %s.",
+                        default_tmp_storage_engine);
+
   }
 
   if (total_ha_2pc > 1 || (1 == total_ha_2pc && opt_bin_log))

sql/sql_table.cc

@@ -4773,7 +4773,11 @@ bool create_table_impl(THD *thd,
   // Check if new table creation is disallowed by the storage engine.
   if (!internal_tmp_table &&
       ha_is_storage_engine_disabled(create_info->db_type))
+  {
+    my_error(ER_DISABLED_STORAGE_ENGINE, MYF(0),
+              ha_resolve_storage_engine_name(create_info->db_type));
     DBUG_RETURN(true);
+  }
 
   if (check_engine(thd, db, table_name, create_info))
     DBUG_RETURN(TRUE);
@@ -8557,7 +8561,11 @@ bool mysql_alter_table(THD *thd, const char *new_db, const char *new_name,
       (alter_info->flags & Alter_info::ALTER_OPTIONS) &&
       (create_info->used_fields & HA_CREATE_USED_ENGINE) &&
        ha_is_storage_engine_disabled(create_info->db_type))
+  {
+    my_error(ER_DISABLED_STORAGE_ENGINE, MYF(0),
+              ha_resolve_storage_engine_name(create_info->db_type));
     DBUG_RETURN(true);
+  }
 
   TABLE *table= table_list->table;
   table->use_all_columns();

sql/sql_tablespace.cc

@@ -145,7 +145,11 @@ int mysql_alter_tablespace(THD *thd, st_alter_tablespace *ts_info)
   if ((ts_info->ts_cmd_type == CREATE_TABLESPACE ||
        ts_info->ts_cmd_type == ALTER_TABLESPACE) &&
       ha_is_storage_engine_disabled(hton))
+  {
+    my_error(ER_DISABLED_STORAGE_ENGINE, MYF(0),
+              ha_resolve_storage_engine_name(hton));
     DBUG_RETURN(true);
+  }
 
   // If this is a tablespace related command, check the tablespace name
   // and acquire and MDL X lock on it.

sql/sys_vars.cc

@@ -1222,6 +1222,48 @@ static bool check_not_null(sys_var *self, THD *thd, set_var *var)
 {
   return var->value && var->value->is_null();
 }
+
+
+/**
+  Check storage engine is not empty and log warning.
+
+  Checks if default_storage_engine or default_tmp_storage_engine is set
+  empty and return true. This method also logs warning if the
+  storage engine set is a disabled storage engine specified in
+  disabled_storage_engines.
+
+  @param self    pointer to system variable object.
+  @param thd     Connection handle.
+  @param var     pointer to set variable object.
+
+  @return  true if the set variable is empty.
+           false if the set variable is not empty.
+*/
+static bool check_storage_engine(sys_var *self, THD *thd, set_var *var)
+{
+  if (check_not_null(self,thd,var))
+    return true;
+
+  if (!opt_bootstrap && !opt_noacl)
+  {
+    char buff[STRING_BUFFER_USUAL_SIZE];
+    String str(buff,sizeof(buff), system_charset_info), *res;
+    res= var->value->val_str(&str);
+    LEX_STRING se_name= { const_cast<char*>(res->ptr()), res->length() };
+
+    plugin_ref plugin;
+    if ((plugin= ha_resolve_by_name(NULL, &se_name, FALSE)))
+    {
+      handlerton *hton= plugin_data<handlerton*>(plugin);
+      if (ha_is_storage_engine_disabled(hton))
+        sql_print_warning("%s is set to a disabled storage engine %s.",
+                          self->name.str, se_name.str);
+      plugin_unlock(NULL, plugin);
+    }
+  }
+  return false;
+}
+
 static bool check_charset(sys_var *self, THD *thd, set_var *var)
 {
   if (!var->value)
@@ -3959,7 +4001,7 @@ static Sys_var_plugin Sys_default_storage_engine(
        "default_storage_engine", "The default storage engine for new tables",
        SESSION_VAR(table_plugin), NO_CMD_LINE,
        MYSQL_STORAGE_ENGINE_PLUGIN, DEFAULT(&default_storage_engine),
-       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_not_null));
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_storage_engine));
 
 const char *internal_tmp_disk_storage_engine_names[] = { "MYISAM", "INNODB", 0};
 static Sys_var_enum Sys_internal_tmp_disk_storage_engine(
@@ -3972,7 +4014,7 @@ static Sys_var_plugin Sys_default_tmp_storage_engine(
        "default_tmp_storage_engine", "The default storage engine for new explict temporary tables",
        SESSION_VAR(temp_table_plugin), NO_CMD_LINE,
        MYSQL_STORAGE_ENGINE_PLUGIN, DEFAULT(&default_tmp_storage_engine),
-       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_not_null));
+       NO_MUTEX_GUARD, NOT_IN_BINLOG, ON_CHECK(check_storage_engine));
 
 #if defined(ENABLED_DEBUG_SYNC)
 /*