#At file:///export/home/x/mysql-5.5-runtime-prereq/ based on revid:jon.hauglid@stripped
3186 Jon Olav Hauglid 2010-11-16
Bug #57663 Concurrent statement using stored function and DROP DATABASE
breaks SBR
This pre-requisite patch refactors the code for dropping tables, used
by DROP TABLE and DROP DATABASE. The patch moves the code for acquiring
metadata locks out of mysql_rm_table_part2() and makes it the
responsibility of the caller. This in preparation of changing the
DROP DATABASE implementation to acquire all metadata locks before any
changes are made. mysql_rm_table_part2() is renamed
mysql_rm_table_no_locks() to reflect the change.
modified:
mysql-test/r/partition_debug_sync.result
mysql-test/t/partition_debug_sync.test
sql/sql_db.cc
sql/sql_table.cc
sql/sql_table.h
=== modified file 'mysql-test/r/partition_debug_sync.result'
--- a/mysql-test/r/partition_debug_sync.result 2010-07-01 13:53:46 +0000
+++ b/mysql-test/r/partition_debug_sync.result 2010-11-16 10:00:12 +0000
@@ -25,7 +25,7 @@ ALTER TABLE t1 REMOVE PARTITIONING;
# Con default
SET DEBUG_SYNC= 'now WAIT_FOR removing_partitioning';
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL waiting_for_alter';
-SET DEBUG_SYNC= 'rm_table_part2_before_delete_table WAIT_FOR partitioning_removed';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_delete_table WAIT_FOR partitioning_removed';
DROP TABLE IF EXISTS t1;
# Con 1
SET SESSION debug= "-d,sleep_before_create_table_no_lock";
@@ -51,12 +51,12 @@ SET DEBUG_SYNC= 'alter_table_before_open
SET DEBUG_SYNC= 'alter_table_before_rename_result_table WAIT_FOR delete_done';
ALTER TABLE t2 REMOVE PARTITIONING;
# Con default
-SET SESSION debug= "+d,sleep_before_part2_delete_table";
+SET SESSION debug= "+d,sleep_before_no_locks_delete_table";
SET DEBUG_SYNC= 'now WAIT_FOR removing_partitions';
-SET DEBUG_SYNC= 'rm_table_part2_before_delete_table SIGNAL waiting_for_alter';
-SET DEBUG_SYNC= 'rm_table_part2_before_binlog SIGNAL delete_done';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_delete_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_binlog SIGNAL delete_done';
DROP TABLE IF EXISTS t2;
-SET SESSION debug= "-d,sleep_before_part2_delete_table";
+SET SESSION debug= "-d,sleep_before_no_locks_delete_table";
# Con 1
ERROR 42S02: Table 'test.t2' doesn't exist
SET DEBUG_SYNC= 'RESET';
=== modified file 'mysql-test/t/partition_debug_sync.test'
--- a/mysql-test/t/partition_debug_sync.test 2010-07-01 13:53:46 +0000
+++ b/mysql-test/t/partition_debug_sync.test 2010-11-16 10:00:12 +0000
@@ -38,7 +38,7 @@ connection default;
--echo # Con default
SET DEBUG_SYNC= 'now WAIT_FOR removing_partitioning';
SET DEBUG_SYNC= 'mdl_acquire_lock_wait SIGNAL waiting_for_alter';
-SET DEBUG_SYNC= 'rm_table_part2_before_delete_table WAIT_FOR partitioning_removed';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_delete_table WAIT_FOR partitioning_removed';
DROP TABLE IF EXISTS t1;
--echo # Con 1
connection con1;
@@ -70,12 +70,12 @@ SET DEBUG_SYNC= 'alter_table_before_rena
--send ALTER TABLE t2 REMOVE PARTITIONING
connection default;
--echo # Con default
-SET SESSION debug= "+d,sleep_before_part2_delete_table";
+SET SESSION debug= "+d,sleep_before_no_locks_delete_table";
SET DEBUG_SYNC= 'now WAIT_FOR removing_partitions';
-SET DEBUG_SYNC= 'rm_table_part2_before_delete_table SIGNAL waiting_for_alter';
-SET DEBUG_SYNC= 'rm_table_part2_before_binlog SIGNAL delete_done';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_delete_table SIGNAL waiting_for_alter';
+SET DEBUG_SYNC= 'rm_table_no_locks_before_binlog SIGNAL delete_done';
DROP TABLE IF EXISTS t2;
-SET SESSION debug= "-d,sleep_before_part2_delete_table";
+SET SESSION debug= "-d,sleep_before_no_locks_delete_table";
--echo # Con 1
connection con1;
--error ER_NO_SUCH_TABLE
=== modified file 'sql/sql_db.cc'
--- a/sql/sql_db.cc 2010-11-15 11:32:49 +0000
+++ b/sql/sql_db.cc 2010-11-16 10:00:12 +0000
@@ -28,6 +28,8 @@
#include "sql_acl.h" // SELECT_ACL, DB_ACLS,
// acl_get, check_grant_db
#include "log_event.h" // Query_log_event
+#include "sql_base.h" // lock_table_names, tdc_remove_table
+#include "sql_handler.h" // mysql_ha_rm_tables
#include <mysys_err.h>
#include "sp.h"
#include "events.h"
@@ -944,6 +946,7 @@ static long mysql_rm_known_files(THD *th
ulong found_other_files=0;
char filePath[FN_REFLEN];
TABLE_LIST *tot_list=0, **tot_list_next_local, **tot_list_next_global;
+ TABLE_LIST *table;
DBUG_ENTER("mysql_rm_known_files");
DBUG_PRINT("enter",("path: %s", org_path));
@@ -1040,8 +1043,39 @@ static long mysql_rm_known_files(THD *th
}
}
}
+
+ /*
+ Disable drop of enabled log tables, must be done before name locking.
+ This check is only needed if we are dropping the "mysql" database.
+ */
+ if ((my_strcasecmp(system_charset_info, MYSQL_SCHEMA_NAME.str, db) == 0))
+ {
+ for (table= tot_list; table; table= table->next_local)
+ {
+ if (check_if_log_table(table->db_length, table->db,
+ table->table_name_length, table->table_name, true))
+ {
+ my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
+ goto err;
+ }
+ }
+ }
+
+ /* mysql_ha_rm_tables() requires a non-null TABLE_LIST. */
+ if (tot_list)
+ mysql_ha_rm_tables(thd, tot_list);
+
+ if (lock_table_names(thd, tot_list, NULL, thd->variables.lock_wait_timeout,
+ MYSQL_OPEN_SKIP_TEMPORARY))
+ goto err;
+
+ for (table= tot_list; table; table= table->next_local)
+ tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name,
+ false);
+
if (thd->killed ||
- (tot_list && mysql_rm_table_part2(thd, tot_list, 1, 0, 1, 1)))
+ (tot_list && mysql_rm_table_no_locks(thd, tot_list, true,
+ false, true, true)))
goto err;
my_dirend(dirp);
=== modified file 'sql/sql_table.cc'
--- a/sql/sql_table.cc 2010-11-12 11:23:17 +0000
+++ b/sql/sql_table.cc 2010-11-16 10:00:12 +0000
@@ -1849,12 +1849,77 @@ bool mysql_rm_table(THD *thd,TABLE_LIST
{
bool error;
Drop_table_error_handler err_handler;
+ TABLE_LIST *table;
DBUG_ENTER("mysql_rm_table");
+ /* Disable drop of enabled log tables, must be done before name locking */
+ for (table= tables; table; table= table->next_local)
+ {
+ if (check_if_log_table(table->db_length, table->db,
+ table->table_name_length, table->table_name, true))
+ {
+ my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
+ DBUG_RETURN(true);
+ }
+ }
+
+ mysql_ha_rm_tables(thd, tables);
+
+ if (!drop_temporary)
+ {
+ if (!thd->locked_tables_mode)
+ {
+ if (lock_table_names(thd, tables, NULL, thd->variables.lock_wait_timeout,
+ MYSQL_OPEN_SKIP_TEMPORARY))
+ DBUG_RETURN(true);
+ for (table= tables; table; table= table->next_local)
+ tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name,
+ false);
+ }
+ else
+ {
+ for (table= tables; table; table= table->next_local)
+ if (table->open_type != OT_BASE_ONLY &&
+ find_temporary_table(thd, table))
+ {
+ /*
+ A temporary table.
+
+ Don't try to find a corresponding MDL lock or assign it
+ to table->mdl_request.ticket. There can't be metadata
+ locks for temporary tables: they are local to the session.
+
+ Later in this function we release the MDL lock only if
+ table->mdl_requeset.ticket is not NULL. Thus here we
+ ensure that we won't release the metadata lock on the base
+ table locked with LOCK TABLES as a side effect of temporary
+ table drop.
+ */
+ DBUG_ASSERT(table->mdl_request.ticket == NULL);
+ }
+ else
+ {
+ /*
+ Not a temporary table.
+
+ Since 'tables' list can't contain duplicates (this is ensured
+ by parser) it is safe to cache pointer to the TABLE instances
+ in its elements.
+ */
+ table->table= find_table_for_mdl_upgrade(thd->open_tables, table->db,
+ table->table_name, false);
+ if (!table->table)
+ DBUG_RETURN(true);
+ table->mdl_request.ticket= table->table->mdl_ticket;
+ }
+ }
+ }
+
/* mark for close and remove all cached entries */
thd->push_internal_handler(&err_handler);
- error= mysql_rm_table_part2(thd, tables, if_exists, drop_temporary, 0, 0);
+ error= mysql_rm_table_no_locks(thd, tables, if_exists, drop_temporary,
+ false, false);
thd->pop_internal_handler();
if (error)
@@ -1863,39 +1928,38 @@ bool mysql_rm_table(THD *thd,TABLE_LIST
DBUG_RETURN(FALSE);
}
-/*
- Execute the drop of a normal or temporary table
- SYNOPSIS
- mysql_rm_table_part2()
- thd Thread handler
- tables Tables to drop
- if_exists If set, don't give an error if table doesn't exists.
- In this case we give an warning of level 'NOTE'
- drop_temporary Only drop temporary tables
- drop_view Allow to delete VIEW .frm
- dont_log_query Don't write query to log files. This will also not
- generate warnings if the handler files doesn't exists
-
- TODO:
- When logging to the binary log, we should log
- tmp_tables and transactional tables as separate statements if we
- are in a transaction; This is needed to get these tables into the
- cached binary log that is only written on COMMIT.
-
- The current code only writes DROP statements that only uses temporary
- tables to the cache binary log. This should be ok on most cases, but
- not all.
-
- RETURN
- 0 ok
- 1 Error
- -1 Thread was killed
+/**
+ Execute the drop of a normal or temporary table.
+
+ @param thd Thread handler
+ @param tables Tables to drop
+ @param if_exists If set, don't give an error if table doesn't exists.
+ In this case we give an warning of level 'NOTE'
+ @param drop_temporary Only drop temporary tables
+ @param drop_view Allow to delete VIEW .frm
+ @param dont_log_query Don't write query to log files. This will also not
+ generate warnings if the handler files doesn't exists
+
+ @retval 0 ok
+ @retval 1 Error
+ @retval -1 Thread was killed
+
+ @note This function assumes that metadata locks have already been taken.
+ It is also assumed that the tables have been removed from TDC.
+
+ @todo When logging to the binary log, we should log
+ tmp_tables and transactional tables as separate statements if we
+ are in a transaction; This is needed to get these tables into the
+ cached binary log that is only written on COMMIT.
+ The current code only writes DROP statements that only uses temporary
+ tables to the cache binary log. This should be ok on most cases, but
+ not all.
*/
-int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
- bool drop_temporary, bool drop_view,
- bool dont_log_query)
+int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
+ bool drop_temporary, bool drop_view,
+ bool dont_log_query)
{
TABLE_LIST *table;
char path[FN_REFLEN + 1], *alias= NULL;
@@ -1909,7 +1973,7 @@ int mysql_rm_table_part2(THD *thd, TABLE
bool non_tmp_table_deleted= 0;
String built_query;
String built_trans_tmp_query, built_non_trans_tmp_query;
- DBUG_ENTER("mysql_rm_table_part2");
+ DBUG_ENTER("mysql_rm_table_no_locks");
/*
Prepares the drop statements that will be written into the binary
@@ -1963,71 +2027,6 @@ int mysql_rm_table_part2(THD *thd, TABLE
}
}
- mysql_ha_rm_tables(thd, tables);
-
- /* Disable drop of enabled log tables, must be done before name locking */
- for (table= tables; table; table= table->next_local)
- {
- if (check_if_log_table(table->db_length, table->db,
- table->table_name_length, table->table_name, 1))
- {
- my_error(ER_BAD_LOG_STATEMENT, MYF(0), "DROP");
- DBUG_RETURN(1);
- }
- }
-
- if (!drop_temporary)
- {
- if (!thd->locked_tables_mode)
- {
- if (lock_table_names(thd, tables, NULL, thd->variables.lock_wait_timeout,
- MYSQL_OPEN_SKIP_TEMPORARY))
- DBUG_RETURN(1);
- for (table= tables; table; table= table->next_local)
- {
- tdc_remove_table(thd, TDC_RT_REMOVE_ALL, table->db, table->table_name,
- FALSE);
- }
- }
- else
- {
- for (table= tables; table; table= table->next_local)
- if (table->open_type != OT_BASE_ONLY &&
- find_temporary_table(thd, table))
- {
- /*
- A temporary table.
-
- Don't try to find a corresponding MDL lock or assign it
- to table->mdl_request.ticket. There can't be metadata
- locks for temporary tables: they are local to the session.
-
- Later in this function we release the MDL lock only if
- table->mdl_requeset.ticket is not NULL. Thus here we
- ensure that we won't release the metadata lock on the base
- table locked with LOCK TABLES as a side effect of temporary
- table drop.
- */
- DBUG_ASSERT(table->mdl_request.ticket == NULL);
- }
- else
- {
- /*
- Not a temporary table.
-
- Since 'tables' list can't contain duplicates (this is ensured
- by parser) it is safe to cache pointer to the TABLE instances
- in its elements.
- */
- table->table= find_table_for_mdl_upgrade(thd->open_tables, table->db,
- table->table_name, FALSE);
- if (!table->table)
- DBUG_RETURN(1);
- table->mdl_request.ticket= table->table->mdl_ticket;
- }
- }
- }
-
for (table= tables; table; table= table->next_local)
{
bool is_trans;
@@ -2040,6 +2039,16 @@ int mysql_rm_table_part2(THD *thd, TABLE
table->table ? (long) table->table->s : (long) -1));
/*
+ If we are in locked tables mode and are dropping a temporary table,
+ the ticket should be NULL to ensure that we don't release a lock
+ on a base table later.
+ */
+ DBUG_ASSERT(!(thd->locked_tables_mode &&
+ table->open_type != OT_BASE_ONLY &&
+ find_temporary_table(thd, table) &&
+ table->mdl_request.ticket != NULL));
+
+ /*
drop_temporary_table may return one of the following error codes:
. 0 - a temporary table was successfully dropped.
. 1 - a temporary table was not found.
@@ -2114,6 +2123,10 @@ int mysql_rm_table_part2(THD *thd, TABLE
table->table= 0;
}
+ /* Check that we have an exclusive lock on the table to be dropped. */
+ DBUG_ASSERT(thd->mdl_context.is_lock_owner(MDL_key::TABLE, table->db,
+ table->table_name,
+ MDL_EXCLUSIVE));
if (thd->killed)
{
error= -1;
@@ -2156,8 +2169,8 @@ int mysql_rm_table_part2(THD *thd, TABLE
built_query.append("`,");
}
}
- DEBUG_SYNC(thd, "rm_table_part2_before_delete_table");
- DBUG_EXECUTE_IF("sleep_before_part2_delete_table",
+ DEBUG_SYNC(thd, "rm_table_no_locks_before_delete_table");
+ DBUG_EXECUTE_IF("sleep_before_no_locks_delete_table",
my_sleep(100000););
error= 0;
if (drop_temporary ||
@@ -2244,7 +2257,7 @@ int mysql_rm_table_part2(THD *thd, TABLE
ER(ER_BAD_TABLE_ERROR), MYF(0),
table->table_name););
}
- DEBUG_SYNC(thd, "rm_table_part2_before_binlog");
+ DEBUG_SYNC(thd, "rm_table_no_locks_before_binlog");
thd->thread_specific_used|= (trans_tmp_table_deleted ||
non_trans_tmp_table_deleted);
error= 0;
=== modified file 'sql/sql_table.h'
--- a/sql/sql_table.h 2010-08-20 17:15:48 +0000
+++ b/sql/sql_table.h 2010-11-16 10:00:12 +0000
@@ -174,8 +174,9 @@ bool mysql_checksum_table(THD* thd, TABL
HA_CHECK_OPT* check_opt);
bool mysql_rm_table(THD *thd,TABLE_LIST *tables, my_bool if_exists,
my_bool drop_temporary);
-int mysql_rm_table_part2(THD *thd, TABLE_LIST *tables, bool if_exists,
- bool drop_temporary, bool drop_view, bool log_query);
+int mysql_rm_table_no_locks(THD *thd, TABLE_LIST *tables, bool if_exists,
+ bool drop_temporary, bool drop_view,
+ bool log_query);
bool quick_rm_table(handlerton *base,const char *db,
const char *table_name, uint flags);
void close_cached_table(THD *thd, TABLE *table);
Attachment: [text/bzr-bundle] bzr/jon.hauglid@oracle.com-20101116100012-kxep9txz2fxy3nmw.bundle
| Thread |
|---|
| • bzr commit into mysql-5.5-runtime branch (jon.hauglid:3186) Bug#57663 | Jon Olav Hauglid | 16 Nov |
