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-rw-r--r--mysql-test/r/lock_multi.result14
-rw-r--r--mysql-test/r/merge.result10
-rw-r--r--mysql-test/t/lock_multi.test26
-rw-r--r--mysql-test/t/merge.test19
-rw-r--r--sql/sql_base.cc108
5 files changed, 153 insertions, 24 deletions
diff --git a/mysql-test/r/lock_multi.result b/mysql-test/r/lock_multi.result
index c440dafb228..99e1f54e762 100644
--- a/mysql-test/r/lock_multi.result
+++ b/mysql-test/r/lock_multi.result
@@ -462,3 +462,17 @@ ERROR 70100: Query execution was interrupted
unlock tables;
# Switching to connection 'default'
drop table t3;
+#
+# Test for the bug where upgradable metadata locks was acquired
+# even if the table to altered was temporary.
+# Bug found while working on the related bug #51240.
+#
+DROP TABLE IF EXISTS t1;
+CREATE TABLE t1 (id INT);
+LOCK TABLE t1 WRITE;
+# Connection con1
+CREATE TEMPORARY TABLE t1 (id INT);
+ALTER TABLE t1 ADD COLUMN j INT;
+# Connection default
+UNLOCK TABLES;
+DROP TABLE t1;
diff --git a/mysql-test/r/merge.result b/mysql-test/r/merge.result
index 7a97ced5c1f..a77f3a75f16 100644
--- a/mysql-test/r/merge.result
+++ b/mysql-test/r/merge.result
@@ -2605,4 +2605,14 @@ ERROR 42000: FUNCTION test.f1 does not exist
execute stmt;
ERROR 42000: FUNCTION test.f1 does not exist
drop table t4, t3, t2, t1;
+#
+# Bug#51240 ALTER TABLE of a locked MERGE table fails
+#
+DROP TABLE IF EXISTS m1, t1;
+CREATE TABLE t1 (c1 INT);
+CREATE TABLE m1 (c1 INT) ENGINE=MRG_MyISAM UNION=(t1);
+LOCK TABLE m1 WRITE;
+ALTER TABLE m1 ADD INDEX (c1);
+UNLOCK TABLES;
+DROP TABLE m1, t1;
End of 6.0 tests
diff --git a/mysql-test/t/lock_multi.test b/mysql-test/t/lock_multi.test
index c34dcb05dd4..6983947d1c4 100644
--- a/mysql-test/t/lock_multi.test
+++ b/mysql-test/t/lock_multi.test
@@ -1092,5 +1092,31 @@ disconnect con2;
drop table t3;
+--echo #
+--echo # Test for the bug where upgradable metadata locks was acquired
+--echo # even if the table to altered was temporary.
+--echo # Bug found while working on the related bug #51240.
+--echo #
+
+--disable_warnings
+DROP TABLE IF EXISTS t1;
+--enable_warnings
+
+CREATE TABLE t1 (id INT);
+LOCK TABLE t1 WRITE;
+
+--echo # Connection con1
+connect (con1, localhost, root);
+CREATE TEMPORARY TABLE t1 (id INT);
+# This alter should not block and timeout.
+ALTER TABLE t1 ADD COLUMN j INT;
+
+--echo # Connection default
+connection default;
+disconnect con1;
+UNLOCK TABLES;
+DROP TABLE t1;
+
+
# Wait till all disconnects are completed
--source include/wait_until_count_sessions.inc
diff --git a/mysql-test/t/merge.test b/mysql-test/t/merge.test
index f0d8960322e..4035752b72d 100644
--- a/mysql-test/t/merge.test
+++ b/mysql-test/t/merge.test
@@ -2089,5 +2089,24 @@ execute stmt;
execute stmt;
drop table t4, t3, t2, t1;
+
+--echo #
+--echo # Bug#51240 ALTER TABLE of a locked MERGE table fails
+--echo #
+
+--disable_warnings
+DROP TABLE IF EXISTS m1, t1;
+--enable_warnings
+
+CREATE TABLE t1 (c1 INT);
+CREATE TABLE m1 (c1 INT) ENGINE=MRG_MyISAM UNION=(t1);
+LOCK TABLE m1 WRITE;
+# This used to cause an error.
+ALTER TABLE m1 ADD INDEX (c1);
+
+UNLOCK TABLES;
+DROP TABLE m1, t1;
+
+
--echo End of 6.0 tests
diff --git a/sql/sql_base.cc b/sql/sql_base.cc
index 0f572350647..0dcfafed882 100644
--- a/sql/sql_base.cc
+++ b/sql/sql_base.cc
@@ -2556,16 +2556,6 @@ bool open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
(int) table_list->lock_type);
/*
- If we are performing DDL operation we also should ensure
- that we will find TABLE instance with upgradable metadata
- lock,
- */
- if ((flags & MYSQL_OPEN_TAKE_UPGRADABLE_MDL) &&
- table_list->lock_type >= TL_WRITE_ALLOW_WRITE &&
- ! table->mdl_ticket->is_upgradable_or_exclusive())
- distance= -1;
-
- /*
Find a table that either has the exact lock type requested,
or has the best suitable lock. In case there is no locked
table that has an equal or higher lock than requested,
@@ -2598,13 +2588,6 @@ bool open_table(THD *thd, TABLE_LIST *table_list, MEM_ROOT *mem_root,
}
if (best_table)
{
- if ((flags & MYSQL_OPEN_TAKE_UPGRADABLE_MDL) &&
- table_list->lock_type >= TL_WRITE_ALLOW_WRITE &&
- ! best_table->mdl_ticket->is_upgradable_or_exclusive())
- {
- my_error(ER_TABLE_NOT_LOCKED_FOR_WRITE, MYF(0), alias);
- DBUG_RETURN(TRUE);
- }
table= best_table;
table->query_id= thd->query_id;
DBUG_PRINT("info",("Using locked table"));
@@ -4354,7 +4337,8 @@ end:
/**
Acquire upgradable (SNW, SNRW) metadata locks on tables to be opened
- for LOCK TABLES or a DDL statement.
+ for LOCK TABLES or a DDL statement. Under LOCK TABLES, we can't take
+ new locks, so use open_tables_check_upgradable_mdl() instead.
@param thd Thread context.
@param tables_start Start of list of tables on which upgradable locks
@@ -4374,10 +4358,15 @@ open_tables_acquire_upgradable_mdl(THD *thd, TABLE_LIST *tables_start,
MDL_request_list mdl_requests;
TABLE_LIST *table;
+ DBUG_ASSERT(!thd->locked_tables_mode);
+
for (table= tables_start; table && table != tables_end;
table= table->next_global)
{
- if (table->lock_type >= TL_WRITE_ALLOW_WRITE)
+ if (table->lock_type >= TL_WRITE_ALLOW_WRITE &&
+ !(table->open_type == OT_TEMPORARY_ONLY ||
+ (table->open_type != OT_BASE_ONLY &&
+ find_temporary_table(thd, table))))
{
table->mdl_request.set_type(table->lock_type > TL_WRITE_ALLOW_READ ?
MDL_SHARED_NO_READ_WRITE :
@@ -4413,6 +4402,58 @@ open_tables_acquire_upgradable_mdl(THD *thd, TABLE_LIST *tables_start,
/**
+ Check for upgradable (SNW, SNRW) metadata locks on tables to be opened
+ for a DDL statement. Under LOCK TABLES, we can't take new locks, so we
+ must check if appropriate locks were pre-acquired.
+
+ @param thd Thread context.
+ @param tables_start Start of list of tables on which upgradable locks
+ should be searched for.
+ @param tables_end End of list of tables.
+
+ @retval FALSE Success.
+ @retval TRUE Failure (e.g. connection was killed)
+*/
+
+static bool
+open_tables_check_upgradable_mdl(THD *thd, TABLE_LIST *tables_start,
+ TABLE_LIST *tables_end)
+{
+ TABLE_LIST *table;
+
+ DBUG_ASSERT(thd->locked_tables_mode);
+
+ for (table= tables_start; table && table != tables_end;
+ table= table->next_global)
+ {
+ if (table->lock_type >= TL_WRITE_ALLOW_WRITE &&
+ !(table->open_type == OT_TEMPORARY_ONLY ||
+ (table->open_type != OT_BASE_ONLY &&
+ find_temporary_table(thd, table))))
+ {
+ /*
+ We don't need to do anything about the found TABLE instance as it
+ will be handled later in open_tables(), we only need to check that
+ an upgradable lock is already acquired. When we enter LOCK TABLES
+ mode, SNRW locks are acquired before all other locks. So if under
+ LOCK TABLES we find that there is TABLE instance with upgradeable
+ lock, all other instances of TABLE for the same table will have the
+ same ticket.
+
+ Note that find_table_for_mdl_upgrade() will report an error if a
+ ticket is not found.
+ */
+ if (!find_table_for_mdl_upgrade(thd->open_tables, table->db,
+ table->table_name, FALSE))
+ return TRUE;
+ }
+ }
+
+ return FALSE;
+}
+
+
+/**
Open all tables in list
@param[in] thd Thread context.
@@ -4498,12 +4539,31 @@ restart:
lock will be reused (thanks to the fact that in recursive case
metadata locks are acquired without waiting).
*/
- if ((flags & MYSQL_OPEN_TAKE_UPGRADABLE_MDL) &&
- ! thd->locked_tables_mode)
+ if (flags & MYSQL_OPEN_TAKE_UPGRADABLE_MDL)
{
- if (open_tables_acquire_upgradable_mdl(thd, *start,
- thd->lex->first_not_own_table(),
- &ot_ctx))
+ /*
+ open_tables_acquire_upgradable_mdl() does not currenly handle
+ these two flags. At this point, that does not matter as they
+ are not used together with MYSQL_OPEN_TAKE_UPGRADABLE_MDL.
+ */
+ DBUG_ASSERT(!(flags & (MYSQL_OPEN_SKIP_TEMPORARY |
+ MYSQL_OPEN_TEMPORARY_ONLY)));
+ if (thd->locked_tables_mode)
+ {
+ /*
+ Under LOCK TABLES, we can't acquire new locks, so we instead
+ need to check if appropriate locks were pre-acquired.
+ */
+ if (open_tables_check_upgradable_mdl(thd, *start,
+ thd->lex->first_not_own_table()))
+ {
+ error= TRUE;
+ goto err;
+ }
+ }
+ else if (open_tables_acquire_upgradable_mdl(thd, *start,
+ thd->lex->first_not_own_table(),
+ &ot_ctx))
{
error= TRUE;
goto err;
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