diff --git a/mysql-test/suite/innodb/r/gap_lock_split.result b/mysql-test/suite/innodb/r/gap_lock_split.result new file mode 100644 index 00000000000..25a3cf711f9 --- /dev/null +++ b/mysql-test/suite/innodb/r/gap_lock_split.result @@ -0,0 +1,27 @@ +SET @save_frequency=@@GLOBAL.innodb_purge_rseg_truncate_frequency; +SET GLOBAL innodb_purge_rseg_truncate_frequency=1; +CREATE TABLE t1(id INT PRIMARY key, val VARCHAR(16000)) ENGINE=InnoDB; +INSERT INTO t1 (id,val) SELECT 2*seq,'x' FROM seq_0_to_1023; +connect con1,localhost,root,,; +START TRANSACTION WITH CONSISTENT SNAPSHOT; +connection default; +DELETE FROM t1 WHERE id=1788; +BEGIN; +SELECT * FROM t1 WHERE id=1788 FOR UPDATE; +id val +connection con1; +COMMIT; +InnoDB 0 transactions not purged +connection default; +INSERT INTO t1 (id,val) VALUES (1787, REPEAT('x',2000)); +connection con1; +SET innodb_lock_wait_timeout=0; +INSERT INTO t1 (id,val) VALUES (1788, 'x'); +ERROR HY000: Lock wait timeout exceeded; try restarting transaction +SELECT * FROM t1 WHERE id=1788 FOR UPDATE; +id val +disconnect con1; +connection default; +COMMIT; +DROP TABLE t1; +SET GLOBAL innodb_purge_rseg_truncate_frequency=@save_frequency; diff --git a/mysql-test/suite/innodb/t/gap_lock_split.test b/mysql-test/suite/innodb/t/gap_lock_split.test new file mode 100644 index 00000000000..462f073ddce --- /dev/null +++ b/mysql-test/suite/innodb/t/gap_lock_split.test @@ -0,0 +1,39 @@ +--source include/have_innodb.inc +--source include/have_sequence.inc +--source include/have_debug.inc + +SET @save_frequency=@@GLOBAL.innodb_purge_rseg_truncate_frequency; +SET GLOBAL innodb_purge_rseg_truncate_frequency=1; + +CREATE TABLE t1(id INT PRIMARY key, val VARCHAR(16000)) ENGINE=InnoDB; +INSERT INTO t1 (id,val) SELECT 2*seq,'x' FROM seq_0_to_1023; + +connect(con1,localhost,root,,); +# Prevent purge. +START TRANSACTION WITH CONSISTENT SNAPSHOT; +connection default; + +DELETE FROM t1 WHERE id=1788; + +BEGIN; +# This will return no result, but should acquire a gap lock. +SELECT * FROM t1 WHERE id=1788 FOR UPDATE; + +connection con1; +COMMIT; +source include/wait_all_purged.inc; +connection default; + +INSERT INTO t1 (id,val) VALUES (1787, REPEAT('x',2000)); + +connection con1; +SET innodb_lock_wait_timeout=0; +--error ER_LOCK_WAIT_TIMEOUT +INSERT INTO t1 (id,val) VALUES (1788, 'x'); +SELECT * FROM t1 WHERE id=1788 FOR UPDATE; +disconnect con1; + +connection default; +COMMIT; +DROP TABLE t1; +SET GLOBAL innodb_purge_rseg_truncate_frequency=@save_frequency; diff --git a/storage/innobase/btr/btr0btr.cc b/storage/innobase/btr/btr0btr.cc index bc85a955f80..b2c3b55cbaa 100644 --- a/storage/innobase/btr/btr0btr.cc +++ b/storage/innobase/btr/btr0btr.cc @@ -2,7 +2,7 @@ Copyright (c) 1994, 2016, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2012, Facebook Inc. -Copyright (c) 2014, 2021, MariaDB Corporation. +Copyright (c) 2014, 2022, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software @@ -2688,8 +2688,8 @@ btr_insert_into_right_sibling( max_size = page_get_max_insert_size_after_reorganize(next_page, 1); /* Extends gap lock for the next page */ - if (!dict_table_is_locking_disabled(cursor->index->table)) { - lock_update_split_left(next_block, block); + if (is_leaf && !dict_table_is_locking_disabled(cursor->index->table)) { + lock_update_node_pointer(block, next_block); } rec = page_cur_tuple_insert( diff --git a/storage/innobase/include/lock0lock.h b/storage/innobase/include/lock0lock.h index 9c3f5d57f01..c7fb219a7d5 100644 --- a/storage/innobase/include/lock0lock.h +++ b/storage/innobase/include/lock0lock.h @@ -1,7 +1,7 @@ /***************************************************************************** -Copyright (c) 1996, 2016, Oracle and/or its affiliates. All Rights Reserved. -Copyright (c) 2017, 2020, MariaDB Corporation. +Copyright (c) 1996, 2022, Oracle and/or its affiliates. +Copyright (c) 2017, 2022, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software @@ -151,6 +151,40 @@ lock_update_copy_and_discard( which copied */ const buf_block_t* block); /*!< in: index page; NOT the root! */ +/** Update gap locks between the last record of the left_block and the +first record of the right_block when a record is about to be inserted +at the start of the right_block, even though it should "naturally" be +inserted as the last record of the left_block according to the +current node pointer in the parent page. + +That is, we assume that the lowest common ancestor of the left_block +and right_block routes the key of the new record to the left_block, +but a heuristic which tries to avoid overflowing left_block has chosen +to insert the record into right_block instead. Said ancestor performs +this routing by comparing the key of the record to a "split point" - +all records greater or equal to than the split point (node pointer) +are in right_block, and smaller ones in left_block. +The split point may be smaller than the smallest key in right_block. + +The gap between the last record on the left_block and the first record +on the right_block is represented as a gap lock attached to the supremum +pseudo-record of left_block, and a gap lock attached to the new first +record of right_block. + +Thus, inserting the new record, and subsequently adjusting the node +pointers in parent pages to values smaller or equal to the new +records' key, will mean that gap will be sliced at a different place +("moved to the left"): fragment of the 1st gap will now become treated +as 2nd. Therefore, we must copy any GRANTED locks from 1st gap to the +2nd gap. Any WAITING locks must be of INSERT_INTENTION type (as no +other GAP locks ever wait for anything) and can stay at 1st gap, as +their only purpose is to notify the requester they can retry +insertion, and there's no correctness requirement to avoid waking them +up too soon. +@param left_block left page +@param right_block right page */ +void lock_update_node_pointer(const buf_block_t *left_block, + const buf_block_t *right_block); /*************************************************************//** Updates the lock table when a page is split to the left. */ void diff --git a/storage/innobase/lock/lock0lock.cc b/storage/innobase/lock/lock0lock.cc index 37e23b56dfc..3398f09b772 100644 --- a/storage/innobase/lock/lock0lock.cc +++ b/storage/innobase/lock/lock0lock.cc @@ -1,7 +1,7 @@ /***************************************************************************** -Copyright (c) 1996, 2017, Oracle and/or its affiliates. All Rights Reserved. -Copyright (c) 2014, 2021, MariaDB Corporation. +Copyright (c) 1996, 2022, Oracle and/or its affiliates. +Copyright (c) 2014, 2022, MariaDB Corporation. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software @@ -3044,6 +3044,17 @@ lock_update_split_right( lock_mutex_exit(); } +void lock_update_node_pointer(const buf_block_t *left_block, + const buf_block_t *right_block) +{ + const ulint h= lock_get_min_heap_no(right_block); + + lock_mutex_enter(); + lock_rec_inherit_to_gap(right_block, left_block, + h, PAGE_HEAP_NO_SUPREMUM); + lock_mutex_exit(); +} + /*************************************************************//** Updates the lock table when a page is merged to the right. */ void