MySQL Bugs: #29900: MySQL does not return an error to the client if INFORMAT SCHEMA fill table fails

Bug #29900	MySQL does not return an error to the client if INFORMAT SCHEMA fill table fails
Submitted:	19 Jul 2007 14:39	Modified:	2 Feb 2010 10:42
Reporter:	Vasil Dimov	Email Updates:
Status:	Verified	Impact on me:	None
Category:	MySQL Server: Information schema	Severity:	S3 (Non-critical)
Version:	5.1.21-23	OS:	Any
Assigned to:		CPU Architecture:	Any

Description:
If ST_SCHEMA_TABLE::fill_table() returns error then MySQL does not return a proper error message to the client and expects next command from client, but the client is waiting for the output of the issued command, for example - "SELECT * FROM INFORMATION_SCHEMA.table"

Following is a typescript from a gdb. It starts from a fill_table function that always returns 1

(gdb) b trx_i_s_common_fill_table
Breakpoint 1 at 0x6d5ea0: file handler/i_s.cc, line 699.
(gdb) r
...
[Switching to Thread 0x8016020f0 (LWP 100316)]

Breakpoint 1, trx_i_s_common_fill_table (thd=0x803764028, tables=0x804610230, cond=0x0)
    at handler/i_s.cc:699
699		return 1;
(gdb) bt
#0  trx_i_s_common_fill_table (thd=0x803764028, tables=0x804610230, cond=0x0)
    at handler/i_s.cc:699
#1  0x000000000062cd03 in get_schema_tables_result (join=0x80460b038, 
    executed_place=PROCESSED_BY_JOIN_EXEC) at sql_show.cc:5260
#2  0x000000000057cdd0 in JOIN::exec (this=0x80460b038) at sql_select.cc:1672
#3  0x000000000057a1b2 in mysql_select (thd=0x803764028, rref_pointer_array=0x803765b98, 
    tables=0x804610230, wild_num=1, fields=@0x803765ab8, conds=0x0, og_num=0, order=0x0, 
    group=0x0, having=0x0, proc_param=0x0, select_options=2684635648, result=0x804610bb0, 
    unit=0x8037655b0, select_lex=0x8037659b0) at sql_select.cc:2273
#4  0x000000000057ea97 in handle_select (thd=0x803764028, lex=0x803765510, 
    result=0x804610bb0, setup_tables_done_option=0) at sql_select.cc:258
#5  0x00000000004f6ae8 in execute_sqlcom_select (thd=0x803764028, all_tables=0x804610230)
    at sql_parse.cc:4493
#6  0x00000000004f85ae in mysql_execute_command (thd=0x803764028) at sql_parse.cc:1838
#7  0x0000000000500891 in mysql_parse (thd=0x803764028, 
    inBuf=0x804610038 "select * from innodb_trx", length=24, 
    found_semicolon=0x7ffffebb5d90) at sql_parse.cc:5395
#8  0x00000000005015b7 in dispatch_command (command=COM_QUERY, thd=0x803764028, 
    packet=0x80377a029 "select * from innodb_trx", packet_length=25) at sql_parse.cc:909
#9  0x0000000000502918 in do_command (thd=0x803764028) at sql_parse.cc:668
#10 0x00000000004f08ac in handle_one_connection (arg=0x803764028) at sql_connect.cc:1094
#11 0x0000000800de89a8 in pthread_getprio () from /lib/libthr.so.3
#12 0x0000000000000000 in ?? ()
Error accessing memory address 0x7ffffebb6000: Bad address.
(gdb) n
755	}
(gdb) 
get_schema_tables_result (join=0x80460b038, executed_place=PROCESSED_BY_JOIN_EXEC)
    at sql_show.cc:5263
5263	        result= 1;
(gdb) 
5264	        join->error= 1;
(gdb) 
5265	        table_list->schema_table_state= executed_place;
(gdb) 
5266	        break;
(gdb) 
5271	  thd->no_warnings_for_error= 0;
(gdb) 
5272	  DBUG_RETURN(result);
(gdb) 
5273	}
(gdb) 
JOIN::exec (this=0x80460b038) at sql_select.cc:1676
1676	    DBUG_VOID_RETURN;
(gdb) 
2117	}
(gdb) 
mysql_select (thd=0x803764028, rref_pointer_array=0x803765b98, tables=0x804610230, 
    wild_num=1, fields=@0x803765ab8, conds=0x0, og_num=0, order=0x0, group=0x0, 
    having=0x0, proc_param=0x0, select_options=2684635648, result=0x804610bb0, 
    unit=0x8037655b0, select_lex=0x8037659b0) at sql_select.cc:2275
2275	  if (thd->cursor && thd->cursor->is_open())
(gdb) 
2285	  if (thd->lex->describe & DESCRIBE_EXTENDED)
(gdb) 
2292	  if (free_join)
(gdb) 
2294	    thd->proc_info="end";
(gdb) 
2295	    err|= select_lex->cleanup();
(gdb) 
2296	    DBUG_RETURN(err || thd->net.report_error);
(gdb) 
2299	}
(gdb) 
handle_select (thd=0x803764028, lex=0x803765510, result=0x804610bb0, 
    setup_tables_done_option=0) at sql_select.cc:260
260	  DBUG_PRINT("info",("res: %d  report_error: %d", res,
(gdb) 
262	  res|= thd->net.report_error;
(gdb) 
263	  if (unlikely(res))
(gdb) 
264	    result->abort();
(gdb) 
266	  DBUG_RETURN(res);
(gdb) 
267	}
(gdb) 
execute_sqlcom_select (thd=0x803764028, all_tables=0x804610230) at sql_parse.cc:4494
4494	      if (result != lex->result)
(gdb) 
4495	        delete result;
(gdb) 
4498	  return res;
(gdb) 
4499	}
(gdb) 
mysql_execute_command (thd=0x803764028) at sql_parse.cc:1839
1839	    break;
(gdb) 
4407	  thd->proc_info="query end";
(gdb) 
4419	  if (thd->one_shot_set && lex->sql_command != SQLCOM_SET_OPTION)
(gdb) 
4428	  if (!(sql_command_flags[lex->sql_command] & CF_HAS_ROW_COUNT))
(gdb) 
4429	    thd->row_count_func= -1;
(gdb) 
4431	  goto finish;
(gdb) 
4437	  if (need_start_waiting)
(gdb) 
4445	  DBUG_RETURN(res || thd->net.report_error);
(gdb) 
4446	}
(gdb) 
mysql_parse (thd=0x803764028, inBuf=0x804610038 "select * from innodb_trx", length=24, 
    found_semicolon=0x7ffffebb5d90) at sql_parse.cc:5396
5396		  query_cache_end_of_result(thd);
(gdb) 
5408	    if (thd->lex->sphead)
(gdb) 
5413	    lex->unit.cleanup();
(gdb) 
5414	    thd->proc_info="freeing items";
(gdb) 
5415	    thd->end_statement();
(gdb) 
5416	    thd->cleanup_after_query();
(gdb) 
5417	    DBUG_ASSERT(thd->change_list.is_empty());
(gdb) 
5425	  DBUG_VOID_RETURN;
(gdb) 
5426	}
(gdb) 
dispatch_command (command=COM_QUERY, thd=0x803764028, 
    packet=0x80377a029 "select * from innodb_trx", packet_length=25) at sql_parse.cc:911
911	    while (!thd->killed && found_semicolon && !thd->net.report_error)
(gdb) 
941	    if (!(specialflag & SPECIAL_NO_PRIOR))
(gdb) 
942	      my_pthread_setprio(pthread_self(),WAIT_PRIOR);
(gdb) 
943	    DBUG_PRINT("info",("query ready"));
(gdb) 
944	    break;
(gdb) 
1258	  if (thd->lock || thd->open_tables || thd->derived_tables ||
(gdb) 
1261	    thd->proc_info="closing tables";
(gdb) 
1262	    close_thread_tables(thd);			/* Free tables */
(gdb) 
1272	  bzero(&thd->transaction.stmt, sizeof(thd->transaction.stmt));
(gdb) 
1273	  if (!thd->active_transaction())
(gdb) 
1274	    thd->transaction.xid_state.xid.null();
(gdb) 
1277	  if (thd->killed_errno() && !thd->net.report_error)
(gdb) 
1279	  if (thd->net.report_error)
(gdb) 
1282	  log_slow_statement(thd);
(gdb) 
1284	  thd->proc_info="cleaning up";
(gdb) 
1285	  VOID(pthread_mutex_lock(&LOCK_thread_count)); // For process list
(gdb) 
1286	  thd->proc_info=0;
(gdb) 
1287	  thd->command=COM_SLEEP;
(gdb) 
1288	  thd->query=0;
(gdb) 
1289	  thd->query_length=0;
(gdb) 
1290	  thread_running--;
(gdb) 
1291	  VOID(pthread_mutex_unlock(&LOCK_thread_count));
(gdb) 
1292	  thd->packet.shrink(thd->variables.net_buffer_length);	// Reclaim some memory
(gdb) 
1293	  free_root(thd->mem_root,MYF(MY_KEEP_PREALLOC));
(gdb) 
1294	  DBUG_RETURN(error);
(gdb) 
1295	}
(gdb) 
do_command (thd=0x803764028) at sql_parse.cc:669
669	}
(gdb) 
handle_one_connection (arg=0x803764028) at sql_connect.cc:1090
1090	    while (!net->error && net->vio != 0 &&
(gdb) 
1093	      net->no_send_error= 0;
(gdb) 
1094	      if (do_command(thd))
(gdb) 

# here it blocks

(gdb) bt
#0  0x00000008013fa79a in read () from /lib/libc.so.7
#1  0x0000000800de7680 in read () from /lib/libthr.so.3
#2  0x0000000000810f1f in vio_read (vio=0x803775168, 
    buf=0x80377a028 "\003select * from innodb_trx", size=4) at viosocket.c:44
#3  0x00000000004d8df6 in my_real_read (net=0x8037640f8, complen=0x7ffffebb5ea8)
    at net_serv.cc:820
#4  0x00000000004d94a9 in my_net_read (net=0x8037640f8) at net_serv.cc:997
#5  0x000000000050278c in do_command (thd=0x803764028) at sql_parse.cc:630
#6  0x00000000004f08ac in handle_one_connection (arg=0x803764028) at sql_connect.cc:1094
#7  0x0000000800de89a8 in pthread_getprio () from /lib/libthr.so.3
#8  0x0000000000000000 in ?? ()
Error accessing memory address 0x7ffffebb6000: Bad address.
(gdb) 

At this ponint the client is hanging, waiting for the output of
SELECT * FROM innodb_trx;

How to repeat:
Create an INFORMATION SCHEMA plugin whose fill table always returns 1

Thank you for a problem report. Please, try to repeat with a newer version, 5.1.22, and inform about the results.

Valeriy, I still get the "deadlock" with 5.1.23-beta.

Do you have some specific changeset in mind that may have fixed this issue?

Fix subject

Vasil,

do you still run into this problem?

Also by using MySQL 5.5?

No feedback was provided for this bug for over a month, so it is
being suspended automatically. If you are able to provide the
information that was originally requested, please do so and change
the status of the bug back to "Open".

Hi,

In 5.1-r3315 the return status from the fill function is ignored - no error is returned to the client or anything printed in the error log.

This behavior is bogus, I am setting the status to "Open".

Thank you for the report.

Verified as described.

To repeat is possible to modify InnoDN Plugin code as follow:

$bzr diff
=== modified file 'storage/innodb_plugin/handler/i_s.cc'
--- storage/innodb_plugin/handler/i_s.cc        2009-10-12 12:00:56 +0000
+++ storage/innodb_plugin/handler/i_s.cc        2010-02-02 10:29:06 +0000
@@ -932,6 +932,7 @@
        trx_i_s_cache_t*        cache;
 
        DBUG_ENTER("trx_i_s_common_fill_table");
+       DBUG_RETURN(1);
 
        /* deny access to non-superusers */
        if (check_global_access(thd, PROCESS_ACL)) {

Then run test:

--source include/have_innodb.inc
-- source suite/innodb/include/have_innodb_plugin.inc
INSTALL PLUGIN INNODB_TRX SONAME 'ha_innodb_plugin.so';

create table t1(f1 int) engine=innodb;
begin;
insert into t1 values(1);

connect (addconroot, localhost, root,,);
connection addconroot;
use information_schema;
show tables;

select * from INNODB_TRX;

See also bug #61677