#At file:///home2/mydev/bzrroot/mysql-6.0-bug20667-2/ based on revid:hema@stripped
2847 Ingo Struewing 2009-07-20
Bug#20667 - Truncate table fails for a write locked table
TRUNCATE TABLE was not allowed under LOCK TABLES.
The patch removes this restriction. mysql_truncate()
does now handle that case.
@ mysql-test/r/merge.result
Bug#20667 - Truncate table fails for a write locked table
Updated test result.
@ mysql-test/r/truncate.result
Bug#20667 - Truncate table fails for a write locked table
Updated test result.
@ mysql-test/t/merge.test
Bug#20667 - Truncate table fails for a write locked table
Updated test case due to now working TRUNCATE under LOCK TABLES.
Added some SELECTs to show that child tables are truncated.
@ mysql-test/t/truncate.test
Bug#20667 - Truncate table fails for a write locked table
Added test.
@ sql/sql_delete.cc
Bug#20667 - Truncate table fails for a write locked table
Added branches for thd->locked_tables_mode.
@ sql/sql_parse.cc
Bug#20667 - Truncate table fails for a write locked table
Deleted rejection of TRUNCATE in case of LOCK TABLES.
modified:
mysql-test/r/merge.result
mysql-test/r/truncate.result
mysql-test/t/merge.test
mysql-test/t/truncate.test
sql/sql_delete.cc
sql/sql_parse.cc
=== modified file 'mysql-test/r/merge.result'
--- a/mysql-test/r/merge.result 2009-04-22 10:02:28 +0000
+++ b/mysql-test/r/merge.result 2009-07-20 12:48:11 +0000
@@ -1053,18 +1053,21 @@ c1
LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
INSERT INTO t1 VALUES (1);
TRUNCATE TABLE t3;
-ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3;
c1
-1
-2
+UNLOCK TABLES;
+SELECT * FROM t1;
+c1
+SELECT * FROM t2;
+c1
#
# Truncate child table under locked tables.
+LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
-ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3;
c1
-1
2
UNLOCK TABLES;
DROP TABLE t1, t2, t3;
@@ -1096,18 +1099,24 @@ INSERT INTO t1 VALUES (1);
CREATE TABLE t4 (c1 INT, INDEX(c1));
LOCK TABLE t4 WRITE;
TRUNCATE TABLE t3;
-ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3;
c1
-1
-2
+SELECT * FROM t1;
+c1
+SELECT * FROM t2;
+c1
#
# Truncate temporary child table under locked tables.
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
-ERROR HY000: Can't execute the given command because you have active locked tables or an active transaction
SELECT * FROM t3;
c1
-1
+2
+SELECT * FROM t1;
+c1
+SELECT * FROM t2;
+c1
2
UNLOCK TABLES;
DROP TABLE t1, t2, t3, t4;
=== modified file 'mysql-test/r/truncate.result'
--- a/mysql-test/r/truncate.result 2007-04-17 10:32:01 +0000
+++ b/mysql-test/r/truncate.result 2009-07-20 12:48:11 +0000
@@ -60,3 +60,28 @@ truncate table v1;
ERROR 42S02: Table 'test.v1' doesn't exist
drop view v1;
drop table t1;
+#
+# Bug#20667 - Truncate table fails for a write locked table
+#
+CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
+LOCK TABLE t1 WRITE;
+INSERT INTO t1 VALUES (1);
+SELECT * FROM t1;
+c1
+1
+TRUNCATE TABLE t1;
+SELECT * FROM t1;
+c1
+UNLOCK TABLES;
+LOCK TABLE t1 READ;
+TRUNCATE TABLE t1;
+ERROR HY000: Table 't1' was locked with a READ lock and can't be updated
+UNLOCK TABLES;
+CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
+LOCK TABLE t2 WRITE;
+TRUNCATE TABLE t1;
+ERROR HY000: Table 't1' was not locked with LOCK TABLES
+UNLOCK TABLES;
+DROP TABLE t1;
+DROP TABLE t2;
+# End of 6.0 tests
=== modified file 'mysql-test/t/merge.test'
--- a/mysql-test/t/merge.test 2009-04-22 10:02:28 +0000
+++ b/mysql-test/t/merge.test 2009-07-20 12:48:11 +0000
@@ -688,12 +688,16 @@ SELECT * FROM t3;
--echo # Truncate MERGE table under locked tables.
LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
INSERT INTO t1 VALUES (1);
---error ER_LOCK_OR_ACTIVE_TRANSACTION
TRUNCATE TABLE t3;
SELECT * FROM t3;
+UNLOCK TABLES;
+SELECT * FROM t1;
+SELECT * FROM t2;
--echo #
--echo # Truncate child table under locked tables.
---error ER_LOCK_OR_ACTIVE_TRANSACTION
+LOCK TABLE t1 WRITE, t2 WRITE, t3 WRITE;
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
SELECT * FROM t3;
UNLOCK TABLES;
@@ -719,14 +723,18 @@ SELECT * FROM t3;
INSERT INTO t1 VALUES (1);
CREATE TABLE t4 (c1 INT, INDEX(c1));
LOCK TABLE t4 WRITE;
---error ER_LOCK_OR_ACTIVE_TRANSACTION
TRUNCATE TABLE t3;
SELECT * FROM t3;
+SELECT * FROM t1;
+SELECT * FROM t2;
--echo #
--echo # Truncate temporary child table under locked tables.
---error ER_LOCK_OR_ACTIVE_TRANSACTION
+INSERT INTO t1 VALUES (1);
+INSERT INTO t2 VALUES (2);
TRUNCATE TABLE t1;
SELECT * FROM t3;
+SELECT * FROM t1;
+SELECT * FROM t2;
UNLOCK TABLES;
DROP TABLE t1, t2, t3, t4;
=== modified file 'mysql-test/t/truncate.test'
--- a/mysql-test/t/truncate.test 2007-04-17 10:32:01 +0000
+++ b/mysql-test/t/truncate.test 2009-07-20 12:48:11 +0000
@@ -69,3 +69,29 @@ drop table t1;
# End of 5.0 tests
+--echo #
+--echo # Bug#20667 - Truncate table fails for a write locked table
+--echo #
+CREATE TABLE t1 (c1 INT) ENGINE=MyISAM;
+LOCK TABLE t1 WRITE;
+INSERT INTO t1 VALUES (1);
+SELECT * FROM t1;
+TRUNCATE TABLE t1;
+SELECT * FROM t1;
+UNLOCK TABLES;
+#
+LOCK TABLE t1 READ;
+--error ER_TABLE_NOT_LOCKED_FOR_WRITE
+TRUNCATE TABLE t1;
+UNLOCK TABLES;
+#
+CREATE TABLE t2 (c1 INT) ENGINE=MyISAM;
+LOCK TABLE t2 WRITE;
+--error ER_TABLE_NOT_LOCKED
+TRUNCATE TABLE t1;
+UNLOCK TABLES;
+DROP TABLE t1;
+DROP TABLE t2;
+
+--echo # End of 6.0 tests
+
=== modified file 'sql/sql_delete.cc'
--- a/sql/sql_delete.cc 2009-06-19 09:28:44 +0000
+++ b/sql/sql_delete.cc 2009-07-20 12:48:11 +0000
@@ -1084,6 +1084,12 @@ bool mysql_truncate(THD *thd, TABLE_LIST
bool error;
uint path_length;
MDL_request *mdl_request= NULL;
+ /*
+ Is set if we're under LOCK TABLES, and used
+ to downgrade the exclusive lock after the
+ table was truncated.
+ */
+ MDL_ticket *mdl_ticket= NULL;
Ha_global_schema_lock_guard global_schema_lock_guard(thd);
DBUG_ENTER("mysql_truncate");
@@ -1129,6 +1135,12 @@ bool mysql_truncate(THD *thd, TABLE_LIST
if (!dont_send_ok)
{
enum legacy_db_type table_type;
+ /*
+ FIXME: Code of TRUNCATE breaks the meta-data
+ locking protocol since it tries to find out the table storage
+ engine and therefore accesses table in some way without holding
+ any kind of meta-data lock.
+ */
mysql_frm_type(thd, path, &table_type);
if (table_type == DB_TYPE_UNKNOWN)
{
@@ -1143,24 +1155,47 @@ bool mysql_truncate(THD *thd, TABLE_LIST
if (table_type == DB_TYPE_NDBCLUSTER)
global_schema_lock_guard.lock();
- /*
- FIXME: Actually code of TRUNCATE breaks meta-data locking protocol since
- tries to get table enging and therefore accesses table in some way
- without holding any kind of meta-data lock.
- */
- mdl_request= MDL_request::create(0, table_list->db,
- table_list->table_name, thd->mem_root);
- mdl_request->set_type(MDL_EXCLUSIVE);
- thd->mdl_context.add_request(mdl_request);
- if (thd->mdl_context.acquire_exclusive_locks())
+
+ mysql_ha_rm_tables(thd, table_list);
+
+ if (thd->locked_tables_mode)
{
- thd->mdl_context.remove_request(mdl_request);
- DBUG_RETURN(TRUE);
+ if (!(table= find_write_locked_table(thd->open_tables, table_list->db,
+ table_list->table_name)))
+ DBUG_RETURN(TRUE);
+ mdl_ticket= table->mdl_ticket;
+ if (wait_while_table_is_used(thd, table, HA_EXTRA_FORCE_REOPEN))
+ goto end;
+ close_all_tables_for_name(thd, table->s, FALSE);
+ }
+ else
+ {
+ /*
+ Even though we could use the previous execution branch
+ here just as well, we must not try to open the table:
+ MySQL manual documents that TRUNCATE can be used to
+ repair a damaged table, i.e. a table that can not be
+ fully "opened". In particular MySQL manual says:
+
+ As long as the table format file tbl_name.frm is valid,
+ the table can be re-created as an empty table with TRUNCATE
+ TABLE, even if the data or index files have become corrupted.
+ */
+
+ mdl_request= MDL_request::create(0, table_list->db,
+ table_list->table_name, thd->mem_root);
+ mdl_request->set_type(MDL_EXCLUSIVE);
+ thd->mdl_context.add_request(mdl_request);
+ if (thd->mdl_context.acquire_exclusive_locks())
+ {
+ thd->mdl_context.remove_request(mdl_request);
+ DBUG_RETURN(TRUE);
+ }
+ pthread_mutex_lock(&LOCK_open);
+ tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table_list->db,
+ table_list->table_name);
+ pthread_mutex_unlock(&LOCK_open);
}
- pthread_mutex_lock(&LOCK_open);
- tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table_list->db,
- table_list->table_name);
- pthread_mutex_unlock(&LOCK_open);
}
/*
@@ -1178,6 +1213,12 @@ bool mysql_truncate(THD *thd, TABLE_LIST
end:
if (!dont_send_ok)
{
+ if (thd->locked_tables_mode && thd->locked_tables_list.reopen_tables(thd))
+ thd->locked_tables_list.unlink_all_closed_tables();
+ /*
+ Even if we failed to reopen some tables,
+ the operation itself succeeded, write the binlog.
+ */
if (!error)
{
/*
@@ -1192,14 +1233,8 @@ end:
thd->mdl_context.release_lock(mdl_request->ticket);
thd->mdl_context.remove_request(mdl_request);
}
- }
- else if (error)
- {
- if (mdl_request)
- {
- thd->mdl_context.release_lock(mdl_request->ticket);
- thd->mdl_context.remove_request(mdl_request);
- }
+ if (mdl_ticket)
+ mdl_ticket->downgrade_exclusive_lock();
}
DBUG_RETURN(error);
=== modified file 'sql/sql_parse.cc'
--- a/sql/sql_parse.cc 2009-07-10 12:31:32 +0000
+++ b/sql/sql_parse.cc 2009-07-20 12:48:11 +0000
@@ -3316,7 +3316,7 @@ end_with_restore_list:
Don't allow this within a transaction because we want to use
re-generate table
*/
- if (thd->locked_tables_mode || thd->active_transaction())
+ if (thd->active_transaction())
{
my_message(ER_LOCK_OR_ACTIVE_TRANSACTION,
ER(ER_LOCK_OR_ACTIVE_TRANSACTION), MYF(0));
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