diff options
| -rw-r--r-- | mysql-test/r/show_check.result | 27 | ||||
| -rw-r--r-- | mysql-test/t/show_check.test | 46 | ||||
| -rw-r--r-- | sql/sql_show.cc | 38 |
3 files changed, 97 insertions, 14 deletions
diff --git a/mysql-test/r/show_check.result b/mysql-test/r/show_check.result index f49366cbf08..c1a75281e0e 100644 --- a/mysql-test/r/show_check.result +++ b/mysql-test/r/show_check.result @@ -1487,3 +1487,30 @@ UNLOCK TABLES; # Connection default COMMIT; DROP TABLE t1; +# +# Bug#55498 SHOW CREATE TRIGGER takes wrong type of metadata lock. +# +DROP TABLE IF EXISTS t1; +CREATE TABLE t1 (a INT); +CREATE TRIGGER t1_bi BEFORE INSERT ON t1 FOR EACH ROW SET new.a = 1; +# Test 1: SHOW CREATE TRIGGER with WRITE locked table. +# Connection con1 +LOCK TABLE t1 WRITE; +# Connection default +SHOW CREATE TRIGGER t1_bi; +Trigger sql_mode SQL Original Statement character_set_client collation_connection Database Collation +t1_bi CREATE DEFINER=`root`@`localhost` TRIGGER t1_bi BEFORE INSERT ON t1 FOR EACH ROW SET new.a = 1 utf8 utf8_general_ci latin1_swedish_ci +# Connection con1 +UNLOCK TABLES; +# Test 2: ALTER TABLE with SHOW CREATE TRIGGER in transaction +# Connection default +START TRANSACTION; +SHOW CREATE TRIGGER t1_bi; +Trigger sql_mode SQL Original Statement character_set_client collation_connection Database Collation +t1_bi CREATE DEFINER=`root`@`localhost` TRIGGER t1_bi BEFORE INSERT ON t1 FOR EACH ROW SET new.a = 1 utf8 utf8_general_ci latin1_swedish_ci +# Connection con1 +ALTER TABLE t1 CHARACTER SET = utf8; +# Connection default +COMMIT; +DROP TRIGGER t1_bi; +DROP TABLE t1; diff --git a/mysql-test/t/show_check.test b/mysql-test/t/show_check.test index 89a43f24296..0323f015e88 100644 --- a/mysql-test/t/show_check.test +++ b/mysql-test/t/show_check.test @@ -1279,6 +1279,52 @@ disconnect con1; DROP TABLE t1; +--echo # +--echo # Bug#55498 SHOW CREATE TRIGGER takes wrong type of metadata lock. +--echo # + +--disable_warnings +DROP TABLE IF EXISTS t1; +--enable_warnings + +CREATE TABLE t1 (a INT); +CREATE TRIGGER t1_bi BEFORE INSERT ON t1 FOR EACH ROW SET new.a = 1; + +--echo # Test 1: SHOW CREATE TRIGGER with WRITE locked table. + +--echo # Connection con1 +connect (con1, localhost, root); +LOCK TABLE t1 WRITE; + +--echo # Connection default +connection default; +# Should not block. +SHOW CREATE TRIGGER t1_bi; + +--echo # Connection con1 +connection con1; +UNLOCK TABLES; + +--echo # Test 2: ALTER TABLE with SHOW CREATE TRIGGER in transaction + +--echo # Connection default +connection default; +START TRANSACTION; +SHOW CREATE TRIGGER t1_bi; + +--echo # Connection con1 +connection con1; +# Should not block. +ALTER TABLE t1 CHARACTER SET = utf8; + +--echo # Connection default +connection default; +COMMIT; +DROP TRIGGER t1_bi; +DROP TABLE t1; +disconnect con1; + + # Wait till all disconnects are completed --source include/wait_until_count_sessions.inc diff --git a/sql/sql_show.cc b/sql/sql_show.cc index 8647237ce72..dc3784eb538 100644 --- a/sql/sql_show.cc +++ b/sql/sql_show.cc @@ -7779,6 +7779,10 @@ TABLE_LIST *get_trigger_table(THD *thd, const sp_name *trg_name) bool show_create_trigger(THD *thd, const sp_name *trg_name) { TABLE_LIST *lst= get_trigger_table(thd, trg_name); + uint num_tables; /* NOTE: unused, only to pass to open_tables(). */ + Table_triggers_list *triggers; + int trigger_idx; + bool error= TRUE; if (!lst) return TRUE; @@ -7790,35 +7794,35 @@ bool show_create_trigger(THD *thd, const sp_name *trg_name) } /* - Open the table by name in order to load Table_triggers_list object. - - NOTE: there is race condition here -- the table can be dropped after - LOCK_open is released. It will be fixed later by acquiring shared - metadata lock on trigger or table name. + Metadata locks taken during SHOW CREATE TRIGGER should be released when + the statement completes as it is an information statement. */ + MDL_ticket *mdl_savepoint= thd->mdl_context.mdl_savepoint(); - uint num_tables; /* NOTE: unused, only to pass to open_tables(). */ - - if (open_tables(thd, &lst, &num_tables, 0)) + /* + Open the table by name in order to load Table_triggers_list object. + */ + if (open_tables(thd, &lst, &num_tables, + MYSQL_OPEN_FORCE_SHARED_HIGH_PRIO_MDL)) { my_error(ER_TRG_CANT_OPEN_TABLE, MYF(0), (const char *) trg_name->m_db.str, (const char *) lst->table_name); - return TRUE; + goto exit; /* Perform closing actions and return error status. */ } - Table_triggers_list *triggers= lst->table->triggers; + triggers= lst->table->triggers; if (!triggers) { my_error(ER_TRG_DOES_NOT_EXIST, MYF(0)); - return TRUE; + goto exit; } - int trigger_idx= triggers->find_trigger_by_name(&trg_name->m_name); + trigger_idx= triggers->find_trigger_by_name(&trg_name->m_name); if (trigger_idx < 0) { @@ -7826,16 +7830,22 @@ bool show_create_trigger(THD *thd, const sp_name *trg_name) (const char *) trg_name->m_db.str, (const char *) lst->table_name); - return TRUE; + goto exit; } - return show_create_trigger_impl(thd, triggers, trigger_idx); + error= show_create_trigger_impl(thd, triggers, trigger_idx); /* NOTE: if show_create_trigger_impl() failed, that means we could not send data to the client. In this case we simply raise the error status and client connection will be closed. */ + +exit: + close_thread_tables(thd); + /* Release any metadata locks taken during SHOW CREATE TRIGGER. */ + thd->mdl_context.rollback_to_savepoint(mdl_savepoint); + return error; } class IS_internal_schema_access : public ACL_internal_schema_access |