3657 Dmitry Shulga 2011-06-23
Fixed Bug#11756013 (formerly known as bug#47870):
BOGUS "THE TABLE MYSQL.PROC IS MISSING,..."
There was a race condition between loading a stored routine
(function/procedure/trigger) specified by fully qualified name
SCHEMA_NAME.PROC_NAME and dropping the stored routine database.
The problem was that there is a window for race condition when one server
thread tries to load a stored routine being executed and the other thread
tries to drop the stored routine schema.
This condition race window exists in implementation of function
mysql_change_db() called by db_load_routine() during loading of stored
routine to cache. Function mysql_change_db() calls check_db_dir_existence()
that might failed because specified database was dropped during concurrent
execution of DROP SCHEMA statement. db_load_routine() calls mysql_change_db()
with flag 'force_switch' set to 'true' value so when referenced db is not found
then my_error() is not called and function mysql_change_db() returns ok.
This shadows information about schema opening error in db_load_routine().
Then db_load_routine() makes attempt to parse stored routine that is failed.
This makes to return error to sp_cache_routines_and_add_tables_aux() but since
during error generation a call to my_error wasn't made and hence
THD::main_da wasn't set we set the generic "mysql.proc table corrupt" error
when running sp_cache_routines_and_add_tables_aux().
The fix is to install an error handler inside db_load_routine() for
the mysql_op_change_db() call, and check later if the ER_BAD_DB_ERROR
was caught.
@ sql/sql_db.cc
Added synchronization point "before_db_dir_check" to emulate a race condition during
processing of CALL/DROP SCHEMA.
modified:
mysql-test/r/sp_sync.result
mysql-test/t/sp_sync.test
sql/sp.cc
sql/sql_db.cc
3656 Inaam Rana 2011-06-17
Bug 12635227 - 61188: DROP TABLE EXTREMELY SLOW
approved by: Marko
rb://681
Coalescing of free buf_page_t descriptors can prove to be one severe
bottleneck in performance of compression. One such workload where it
hurts badly is DROP TABLE. This patch removes buf_page_t allocations
from buf_buddy and uses ut_malloc instead.
In order to further reduce overhead of colaescing we no longer attempt
to coalesce a block if the corresponding free_list is less than 16 in
size.
modified:
storage/innodb_plugin/ChangeLog
storage/innodb_plugin/btr/btr0cur.c
storage/innodb_plugin/buf/buf0buddy.c
storage/innodb_plugin/buf/buf0buf.c
storage/innodb_plugin/buf/buf0lru.c
storage/innodb_plugin/include/buf0buddy.h
storage/innodb_plugin/include/buf0buddy.ic
storage/innodb_plugin/include/buf0buf.h
storage/innodb_plugin/include/buf0buf.ic
storage/innodb_plugin/include/buf0lru.h
storage/innodb_plugin/include/buf0types.h
=== modified file 'mysql-test/r/sp_sync.result'
--- a/mysql-test/r/sp_sync.result 2010-01-12 14:16:26 +0000
+++ b/mysql-test/r/sp_sync.result 2011-06-23 13:41:04 +0000
@@ -1,4 +1,4 @@
-Tests of syncronization of stored procedure execution.
+Tests of synchronization of stored procedure execution.
#
# Bug#48157: crash in Item_field::used_tables
#
@@ -20,4 +20,16 @@ SET DEBUG_SYNC = 'now SIGNAL go';
# code, this test statement will hang.
DROP TABLE t1, t2;
DROP PROCEDURE p1;
+#
+# test for bug#11756013
+#
+DROP SCHEMA IF EXISTS s1;
+CREATE SCHEMA s1;
+CREATE PROCEDURE s1.p1() BEGIN END;
+SET DEBUG_SYNC='before_db_dir_check SIGNAL check_db WAIT_FOR dropped_schema';
+CALL s1.p1;
+SET DEBUG_SYNC='now WAIT_FOR check_db';
+DROP SCHEMA s1;
+SET DEBUG_SYNC='now SIGNAL dropped_schema';
+ERROR 42000: Unknown database 's1'
SET DEBUG_SYNC = 'RESET';
=== modified file 'mysql-test/t/sp_sync.test'
--- a/mysql-test/t/sp_sync.test 2010-01-15 08:51:39 +0000
+++ b/mysql-test/t/sp_sync.test 2011-06-23 13:41:04 +0000
@@ -1,7 +1,10 @@
# This test should work in embedded server after mysqltest is fixed
-- source include/not_embedded.inc
---echo Tests of syncronization of stored procedure execution.
+# Save the initial number of concurrent sessions
+--source include/count_sessions.inc
+
+--echo Tests of synchronization of stored procedure execution.
--source include/have_debug_sync.inc
@@ -54,5 +57,31 @@ connection default;
DROP TABLE t1, t2;
DROP PROCEDURE p1;
+--echo #
+--echo # test for bug#11756013
+--echo #
+--disable_warnings
+DROP SCHEMA IF EXISTS s1;
+--enable_warnings
+CREATE SCHEMA s1;
+CREATE PROCEDURE s1.p1() BEGIN END;
+
+connect (con3, localhost, root);
+SET DEBUG_SYNC='before_db_dir_check SIGNAL check_db WAIT_FOR dropped_schema';
+--send CALL s1.p1
+
+connection default;
+SET DEBUG_SYNC='now WAIT_FOR check_db';
+DROP SCHEMA s1;
+SET DEBUG_SYNC='now SIGNAL dropped_schema';
+
+connection con3;
+--error ER_BAD_DB_ERROR
+--reap
+connection default;
+disconnect con3;
+
SET DEBUG_SYNC = 'RESET';
+# Wait till we reached the initial number of concurrent sessions
+--source include/wait_until_count_sessions.inc
=== modified file 'sql/sp.cc'
--- a/sql/sp.cc 2010-06-11 12:52:06 +0000
+++ b/sql/sp.cc 2011-06-23 13:41:04 +0000
@@ -708,6 +708,37 @@ Silence_deprecated_warning::handle_error
}
+class Bad_db_error_handler : public Internal_error_handler
+{
+public:
+ Bad_db_error_handler()
+ :m_error_caught(false)
+ {}
+
+ virtual bool handle_error(uint sql_errno, const char *message,
+ MYSQL_ERROR::enum_warning_level level,
+ THD *thd);
+
+ bool error_caught() const { return m_error_caught; }
+
+private:
+ bool m_error_caught;
+};
+
+bool
+Bad_db_error_handler::handle_error(uint sql_errno, const char *message,
+ MYSQL_ERROR::enum_warning_level level,
+ THD *thd)
+{
+ if (sql_errno == ER_BAD_DB_ERROR)
+ {
+ m_error_caught= true;
+ return true;
+ }
+ return false;
+}
+
+
static int
db_load_routine(THD *thd, int type, sp_name *name, sp_head **sphp,
ulong sql_mode, const char *params, const char *returns,
@@ -725,7 +756,7 @@ db_load_routine(THD *thd, int type, sp_n
ha_rows old_select_limit= thd->variables.select_limit;
sp_rcontext *old_spcont= thd->spcont;
Silence_deprecated_warning warning_handler;
-
+ Bad_db_error_handler db_not_exists_handler;
char definer_user_name_holder[USERNAME_LENGTH + 1];
LEX_STRING definer_user_name= { definer_user_name_holder,
USERNAME_LENGTH };
@@ -766,6 +797,7 @@ db_load_routine(THD *thd, int type, sp_n
goto end;
}
+ thd->push_internal_handler(&db_not_exists_handler);
/*
Change the current database (if needed).
@@ -776,9 +808,17 @@ db_load_routine(THD *thd, int type, sp_n
&cur_db_changed))
{
ret= SP_INTERNAL_ERROR;
+ thd->pop_internal_handler();
goto end;
}
+ thd->pop_internal_handler();
+ if (db_not_exists_handler.error_caught())
+ {
+ ret= SP_INTERNAL_ERROR;
+ my_error(ER_BAD_DB_ERROR, MYF(0), name->m_db.str);
+ goto end;
+ }
thd->spcont= NULL;
{
=== modified file 'sql/sql_db.cc'
--- a/sql/sql_db.cc 2010-12-10 07:48:50 +0000
+++ b/sql/sql_db.cc 2011-06-23 13:41:04 +0000
@@ -26,6 +26,7 @@
#ifdef __WIN__
#include <direct.h>
#endif
+#include "debug_sync.h"
#define MAX_DROP_TABLE_Q_LEN 1024
@@ -1702,6 +1703,8 @@ bool mysql_change_db(THD *thd, const LEX
}
#endif
+ DEBUG_SYNC(thd, "before_db_dir_check");
+
if (check_db_dir_existence(new_db_file_name.str))
{
if (force_switch)
Attachment: [text/bzr-bundle] bzr/dmitry.shulga@oracle.com-20110623134104-5ao4el9lwz95vsb3.bundle
| Thread |
|---|
| • bzr push into mysql-5.1 branch (Dmitry.Shulga:3656 to 3657) Bug#47870Bug#11756013 | Dmitry Shulga | 23 Jun |
