database/mariadb
1
0
Fork 0
mirror of https://github.com/MariaDB/server.git synced 2025-07-30 16:24:05 +03:00
Code Activity

MDEV-17595 - ALTER TABLE ADD FOREIGN KEY crash

Browse Source 
ALTER TABLE ... ADD FOREIGN KEY may trigger assertion failure when
it has LOCK=EXCLUSIVE clause or concurrent FLUSH TABLES is being
executed.

In both cases being altered table is marked as flushed, which forces
subsequent attempt to open parent table to re-open. Which in turn is
not allowed while transaction is running.

Rather than opening parent table, just take appropriate MDL lock.

Also removed table_already_fk_prelocked() check: MDL itself has much
better methods to handle duplicate locks. E.g. the former won't acquire
MDL_SHARED_NO_WRITE if it already has MDL_SHARED_READ.
This commit is contained in:
Sergey Vojtovich
2019-03-07 13:43:53 +04:00
parent 0a0eed8016
commit 149b754768
3 changed files with 36 additions and 12 deletions
Download Patch File Download Diff File Expand all files Collapse all files

13
mysql-test/suite/innodb/r/foreign-keys.result
View File

@ -87,3 +87,16 @@ drop table t3;
drop table t2;
drop table t1;
set debug_sync='reset';
#
# MDEV-17595 - Server crashes in copy_data_between_tables or
# Assertion `thd->transaction.stmt.is_empty() ||
# (thd->state_flags & Open_tables_state::BACKUPS_AVAIL)'
# fails in close_tables_for_reopen upon concurrent
# ALTER TABLE and FLUSH
#
CREATE TABLE t1 (a INT, KEY(a)) ENGINE=InnoDB;
INSERT INTO t1 VALUES(1),(2);
CREATE TABLE t2 (b INT, KEY(b)) ENGINE=InnoDB;
INSERT INTO t2 VALUES(2);
ALTER TABLE t2 ADD FOREIGN KEY(b) REFERENCES t1(a), LOCK=EXCLUSIVE;
DROP TABLE t2, t1;