LOAD DATA consuming 100% CPU and never finishing

[Alkaagr81]

Bug Report

Please answer these questions before submitting your issue. Thanks!

<!-- Create loaddata3.bat file -->

number     row data
1          row 1     
2          row 2     
error      12345678901234567890123456789012345678901234567890
3          row 3     
wrong end  12345678901234567890123456789012345678901234567890

1. Minimal reproduce step (Required)

create table t1 (a int, b char(10)) charset latin1;
load data local infile '~/pingcap/Github/tidb-test/MYSQL_TEST/std_data/loaddata3.dat' ignore into table t1 fields terminated by '' enclosed by '' ignore 1 lines;
select * from t1;

2. What did you expect to see? (Required)

mysql> create table t1 (a int, b char(10)) charset latin1;
Query OK, 0 rows affected (0.03 sec)

mysql> load data local infile '~/pingcap/Github/tidb-test/MYSQL_TEST/std_data/loaddata3.dat' ignore into table t1 fields terminated by '' enclosed by '' ignore 1 lines;
Query OK, 5 rows affected, 4 warnings (0.02 sec)
Records: 5  Deleted: 0  Skipped: 0  Warnings: 4

mysql> select * from t1;
+------+------------+
| a    | b          |
+------+------------+
|    1 | row 1      |
|    2 | row 2      |
|    0 | 1234567890 |
|    3 | row 3      |
|    0 | 1234567890 |
+------+------------+
5 rows in set (0.00 sec)

3. What did you see instead (Required)

Nothing for tidb

4. What is your TiDB version? (Required)

| Release Version: v5.4.0
Edition: Community
Git Commit Hash: 55f3b24c1c9f506bd652ef1d162283541e428872
Git Branch: heads/refs/tags/v5.4.0
UTC Build Time: 2022-01-25 08:41:05
GoVersion: go1.16.4
Race Enabled: false
TiKV Min Version: v3.0.0-60965b006877ca7234adaced7890d7b029ed1306
Check Table Before Drop: false |

[morgo]

I can reproduce this issue against master:

From a simple LOAD DATA, the statement never finishes.

[morgo]

Also including from SHOW PROCESSLIST. The connection does not respond to KILL:

tidb> kill tidb 415;
Query OK, 0 rows affected (0.00 sec)

tidb> show processlist;
+------+------+-----------------+------+---------+------+------------+------------------------------------------------------------------------------------------------------+
| Id   | User | Host            | db   | Command | Time | State      | Info                                                                                                 |
+------+------+-----------------+------+---------+------+------------+------------------------------------------------------------------------------------------------------+
|  419 | root | 127.0.0.1:42456 | NULL | Query   |    0 | autocommit | show processlist                                                                                     |
|  415 | root | 127.0.0.1:42452 | test | Query   |  318 | autocommit | load data local infile '/tmp/t'  ignore into table t1 fields terminated by '' enclosed by '' ignore  |
+------+------+-----------------+------+---------+------+------------+------------------------------------------------------------------------------------------------------+
2 rows in set (0.00 sec)