Commit 0235a528 authored by Vlad Lesin's avatar Vlad Lesin

MDEV-10087 mysqld_update()/mysql_delete() continues execution even after...

MDEV-10087 mysqld_update()/mysql_delete() continues execution even after subquery with JOIN gets error from storage engine

The issue is that record_should_be_deleted() returns true in
mysql_delete() even if sub-select with join gets error from storage
engine when DELETE FROM ... WHERE ... IN (SELECT ...) statement is
executed.

The same is true for mysql_update() where select->skip_record() returns
true even if sub-select with join gets error from storage engine.

In the test case if sub-select is chosen as deadlock victim the whole
transaction is rolled back during sub-select execution, but
mysql_delete()/mysql_update() continues transaction execution and invokes
table->delete_row() as record_should_be_deleted() wrongly returns true
in mysql_delete() and table->update_row() as select->skip_record(thd)
wrongly returns 1 for mysql_update().

record_should_be_deleted() wrogly returns true because thd->is_error()
returns false SQL_SELECT::skip_record() invoked from
record_should_be_deleted().

It's supposed that THD error should be set in rr_handle_error() called
from rr_sequential() during sub-select JOIN::exec_inner() execution.

But rr_handle_error() does not set THD error because
READ_RECORD::print_error is not set in JOIN_TAB::read_record.

READ_RECORD::print_error should be initialized in
init_read_record()/init_read_record_idx(). But make_join_readinfo() does
not invoke init_read_record()/init_read_record_idx() for
JOIN_TAB::read_record.

The fix is to set JOIN_TAB::read_record.print_error in
make_join_readinfo(), i.e. in the same place where
JOIN_TAB::read_record.table is set.

Reviewed by Sergey Petrunya.
parent 0ffdcf67
CREATE TABLE t1 (
pkey int NOT NULL PRIMARY KEY,
c int
) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1,1);
CREATE TABLE t2 (
pkey int NOT NULL PRIMARY KEY,
c int
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO t2 VALUES (2, NULL);
CREATE TABLE t3 (c int) engine = InnoDB;
INSERT INTO t3 VALUES (10), (20), (30), (40), (50);
connect con1, localhost,root,,;
connection default;
START TRANSACTION;
UPDATE t3 SET c=c+1000;
SELECT * FROM t1 FOR UPDATE;
pkey c
1 1
connection con1;
START TRANSACTION;
DELETE FROM t2 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey);
connection default;
SELECT * FROM t2 FOR UPDATE;
pkey c
2 NULL
COMMIT;
connection con1;
ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
COMMIT;
connection default;
START TRANSACTION;
UPDATE t3 SET c=c+1000;
SELECT * FROM t1 FOR UPDATE;
pkey c
1 1
connection con1;
START TRANSACTION;
UPDATE t2 SET pkey=pkey+10 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey);
connection default;
SELECT * FROM t2 FOR UPDATE;
pkey c
2 NULL
COMMIT;
connection con1;
ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
COMMIT;
disconnect con1;
connection default;
DROP TABLE t1,t2,t3;
--source include/have_innodb.inc
--source include/count_sessions.inc
CREATE TABLE t1 (
pkey int NOT NULL PRIMARY KEY,
c int
) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1,1);
CREATE TABLE t2 (
pkey int NOT NULL PRIMARY KEY,
c int
) ENGINE=InnoDB DEFAULT CHARSET=latin1;
INSERT INTO t2 VALUES (2, NULL);
# The following table is to increase tansaction weight on deadlock resolution
CREATE TABLE t3 (c int) engine = InnoDB;
INSERT INTO t3 VALUES (10), (20), (30), (40), (50);
--let $i= 2
--let $delete= 2
--let $update= 1
--connect(con1, localhost,root,,)
while($i) {
--connection default
START TRANSACTION; # trx 1
# The following update is necessary to increase the transaction weight, which is
# calculated as the number of locks + the number of undo records during deadlock
# report. Victim's transaction should have minimum weight. We need trx 2 to be
# choosen as victim, that's why we need to increase the current transaction
# weight.
UPDATE t3 SET c=c+1000;
SELECT * FROM t1 FOR UPDATE;
--connection con1
START TRANSACTION; # trx 2
# 1) read record from t2, lock it
# 2) check if the read record should be deleted, i.e. read record from t1,
# as the record from t1 is locked by trx 1, the subselect will be suspended.
# see 'while' loop in mysql_delete() or mysql_update() and
# select->skip_record(thd) call for details.
if ($i == $delete) {
--send DELETE FROM t2 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey)
}
if ($i == $update) {
--send UPDATE t2 SET pkey=pkey+10 WHERE c NOT IN (SELECT ref_0.pkey FROM t1 AS ref_0 INNER JOIN t1 AS ref_1 ON ref_0.c = ref_0.pkey)
}
--connection default
let $wait_condition=
SELECT count(*) = 1 FROM information_schema.processlist
WHERE (state = 'Sending data' OR state = "Updating")
AND (info LIKE 'delete from t2 where%' OR
info LIKE 'UPDATE t2 SET pkey=pkey+10 WHERE%');
--source include/wait_condition.inc
# The record from t2 is locked by the previous delete, so trx 2 is waiting for
# trx 1, and trx 1 will be blocked by trx 2 with the following SELECT. So we
# have deadlock here. And trx 2 is chosen as deadlock victim as trx 1 has
# greater weight.
SELECT * FROM t2 FOR UPDATE;
COMMIT;
--connection con1
# If the bug is not fixed, there will be assertion failure as
# mysql_delete()/mysql_update() will continue execution despite its subselect
# got deadlock error
--error ER_LOCK_DEADLOCK
--reap
COMMIT;
--dec $i
}
--disconnect con1
--connection default
DROP TABLE t1,t2,t3;
--source include/wait_until_count_sessions.inc
......@@ -12509,6 +12509,7 @@ make_join_readinfo(JOIN *join, ulonglong options, uint no_jbuf_after)
uint jcl= tab->used_join_cache_level;
tab->read_record.table= table;
tab->read_record.unlock_row= rr_unlock_row;
tab->read_record.print_error= true;
tab->sorted= sorted;
sorted= 0; // only first must be sorted
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment