| Bug #56134 | mysql_admin_table should check the return value of open_and_lock_tables | ||
|---|---|---|---|
| Submitted: | 20 Aug 2010 6:16 | Modified: | 11 May 2011 8:41 |
| Reporter: | Yuan WANG | Email Updates: | |
| Status: | Can't repeat | Impact on me: | |
| Category: | MySQL Server: DDL | Severity: | S3 (Non-critical) |
| Version: | 5.1.49 | OS: | Any |
| Assigned to: | Jon Olav Hauglid | CPU Architecture: | Any |
[21 Aug 2010 11:48]
Sveta Smirnova
Thank you for the report.
Verified as described.
To repeat modify sources as follow:
$bzr diff
=== modified file 'storage/myisam/ha_myisam.cc'
--- storage/myisam/ha_myisam.cc 2010-03-02 09:45:50 +0000
+++ storage/myisam/ha_myisam.cc 2010-08-21 10:47:21 +0000
@@ -1879,6 +1879,7 @@
int ha_myisam::external_lock(THD *thd, int lock_type)
{
+ DBUG_EXECUTE_IF("get_error_in_mysql_admin_table", {return HA_ADMIN_INTERNAL_ERROR;});
return mi_lock_database(file, !table->s->tmp_table ?
lock_type : ((lock_type == F_UNLCK) ?
F_UNLCK : F_EXTRA_LCK));
Then create test for MTR and run it:
create table t1(f1 int);
insert into t1 values(1),(2),(3);
SET SESSION debug="+d,get_error_in_mysql_admin_table";
optimize table t1;
You get:
=====mysql-5.1=====
=====bug56134=====
create table t1(f1 int);
insert into t1 values(1),(2),(3);
SET SESSION debug="+d,get_error_in_mysql_admin_table";
optimize table t1;
Table Op Msg_type Msg_text
test.t1 optimize Error Can't lock file (errno: -4)
test.t1 optimize status OK
Why status is OK?
[11 May 2011 8:41]
Jon Olav Hauglid
In 5.5+ we check the result of open_and_lock_tables() in mysql_admin_table(). Closing as "Can't reproduce" since the bug was triaged to be fixed in 5.6+ only.
Description: We found a problem of function mysql_admin_table() when developing a customized storage engine. mysql_admin_table() calls open_and_lock_tables(), as shown in the following codes. if (view_operator_func == NULL) table->required_type=FRMTYPE_TABLE; open_and_lock_tables(thd, table); thd->no_warnings_for_error= 0; Our storage engine may fail in locking tables due to lock wait timeout. In this case, we return error in external_lock() and we thought then MySQL will abort the operation. However, we found that even when our storage engine return error in external_lock(), MySQL will continue. We read the codes and we think the problem is in the codes above in function mysql_admin_table(), where open_and_lock_tables() is called to lock the table but the return value of it is not checked. We think the return value of open_and_lock_tables() should be checked and if it failed MySQL should abort the operation. How to repeat: We currently are not able to construct a test case with other storage engines. Suggested fix: Check the return value of open_and_lock_tables() and abort the operation if it fails.