mirrors/postgres
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

Make RelationFlushRelation() work without ResourceOwner during abort

Browse Source 
ReorderBufferImmediateInvalidation() executes invalidation messages in
an aborted transaction. However, RelationFlushRelation sometimes
required a valid resource owner, to temporarily increment the refcount
of the relache entry. Commit b8bff07daa worked around that in the main
subtransaction abort function, AbortSubTransaction(), but missed this
similar case in ReorderBufferImmediateInvalidation().

To fix, introduce a separate function to invalidate a relcache
entry. It does the same thing as RelationClearRelation(rebuild==true)
does when outside a transaction, but can be called without
incrementing the refcount.

Add regression test. Before this fix, it failed with:

ERROR: ResourceOwnerEnlarge called after release started

Reported-by: Alexander Lakhin <exclusion@gmail.com>
Discussion: https://www.postgresql.org/message-id/e56be7d9-14b1-664d-0bfc-00ce9772721c@gmail.com
This commit is contained in:
Heikki Linnakangas 2024-06-06 18:56:28 +03:00
parent 505c008ca3
commit e6cd857726
4 changed files with 122 additions and 20 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

48
contrib/test_decoding/expected/decoding_in_xact.out
View File

@ -79,6 +79,54 @@ SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'inc
COMMIT
(6 rows)
-- Decoding works in transaction that issues DDL
--
-- We had issues handling relcache invalidations with these, see
-- https://www.postgresql.org/message-id/e56be7d9-14b1-664d-0bfc-00ce9772721c@gmail.com
CREATE TABLE tbl_created_outside_xact(id SERIAL PRIMARY KEY);
BEGIN;
-- TRUNCATE changes the relfilenode and sends relcache invalidation
TRUNCATE tbl_created_outside_xact;
INSERT INTO tbl_created_outside_xact(id) VALUES('1');
-- don't show yet, haven't committed
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
------
(0 rows)
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
--------------------------------------------------------------
BEGIN
table public.tbl_created_outside_xact: TRUNCATE: (no-flags)
table public.tbl_created_outside_xact: INSERT: id[integer]:1
COMMIT
(4 rows)
SET debug_logical_replication_streaming = immediate;
BEGIN;
CREATE TABLE tbl_created_in_xact(id SERIAL PRIMARY KEY);
INSERT INTO tbl_created_in_xact VALUES (1);
CHECKPOINT; -- Force WAL flush, so that the above changes will be streamed
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
data
------------------------------------------
opening a streamed block for transaction
streaming change for transaction
closing a streamed block for transaction
(3 rows)
COMMIT;
RESET debug_logical_replication_streaming;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
data
---------------------------------------------------------
BEGIN
table public.tbl_created_in_xact: INSERT: id[integer]:1
COMMIT
(3 rows)
SELECT 'stop' FROM pg_drop_replication_slot('regression_slot');
?column?
----------

27
contrib/test_decoding/sql/decoding_in_xact.sql
View File

@ -38,4 +38,31 @@ COMMIT;
INSERT INTO nobarf(data) VALUES('3');
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
-- Decoding works in transaction that issues DDL
--
-- We had issues handling relcache invalidations with these, see
-- https://www.postgresql.org/message-id/e56be7d9-14b1-664d-0bfc-00ce9772721c@gmail.com
CREATE TABLE tbl_created_outside_xact(id SERIAL PRIMARY KEY);
BEGIN;
-- TRUNCATE changes the relfilenode and sends relcache invalidation
TRUNCATE tbl_created_outside_xact;
INSERT INTO tbl_created_outside_xact(id) VALUES('1');
-- don't show yet, haven't committed
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
COMMIT;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SET debug_logical_replication_streaming = immediate;
BEGIN;
CREATE TABLE tbl_created_in_xact(id SERIAL PRIMARY KEY);
INSERT INTO tbl_created_in_xact VALUES (1);
CHECKPOINT; -- Force WAL flush, so that the above changes will be streamed
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1', 'stream-changes', '1');
COMMIT;
RESET debug_logical_replication_streaming;
SELECT data FROM pg_logical_slot_get_changes('regression_slot', NULL, NULL, 'include-xids', '0', 'skip-empty-xacts', '1');
SELECT 'stop' FROM pg_drop_replication_slot('regression_slot');

13
src/backend/access/transam/xact.c
View File

@ -5279,20 +5279,7 @@ AbortSubTransaction(void)
AtEOSubXact_RelationCache(false, s->subTransactionId,
s->parent->subTransactionId);
/*
* AtEOSubXact_Inval sometimes needs to temporarily bump the refcount
* on the relcache entries that it processes. We cannot use the
* subtransaction's resource owner anymore, because we've already
* started releasing it. But we can use the parent resource owner.
*/
CurrentResourceOwner = s->parent->curTransactionOwner;
AtEOSubXact_Inval(false);
CurrentResourceOwner = s->curTransactionOwner;
ResourceOwnerRelease(s->curTransactionOwner,
RESOURCE_RELEASE_LOCKS,
false, false);

48
src/backend/utils/cache/relcache.c vendored
View File

@ -275,6 +275,7 @@ static HTAB *OpClassCache = NULL;
static void RelationCloseCleanup(Relation relation);
static void RelationDestroyRelation(Relation relation, bool remember_tupdesc);
static void RelationInvalidateRelation(Relation relation);
static void RelationClearRelation(Relation relation, bool rebuild);
static void RelationReloadIndexInfo(Relation relation);
@ -2512,6 +2513,31 @@ RelationDestroyRelation(Relation relation, bool remember_tupdesc)
pfree(relation);
}
/*
* RelationInvalidateRelation - mark a relation cache entry as invalid
*
* An entry that's marked as invalid will be reloaded on next access.
*/
static void
RelationInvalidateRelation(Relation relation)
{
/*
* Make sure smgr and lower levels close the relation's files, if they
* weren't closed already. If the relation is not getting deleted, the
* next smgr access should reopen the files automatically. This ensures
* that the low-level file access state is updated after, say, a vacuum
* truncation.
*/
RelationCloseSmgr(relation);
/* Free AM cached data, if any */
if (relation->rd_amcache)
pfree(relation->rd_amcache);
relation->rd_amcache = NULL;
relation->rd_isvalid = false;
}
/*
* RelationClearRelation
*
@ -2846,16 +2872,30 @@ RelationFlushRelation(Relation relation)
* New relcache entries are always rebuilt, not flushed; else we'd
* forget the "new" status of the relation. Ditto for the
* new-relfilenumber status.
*
* The rel could have zero refcnt here, so temporarily increment the
* refcnt to ensure it's safe to rebuild it. We can assume that the
* current transaction has some lock on the rel already.
*/
if (IsTransactionState() && relation->rd_droppedSubid == InvalidSubTransactionId)
{
/*
* The rel could have zero refcnt here, so temporarily increment
* the refcnt to ensure it's safe to rebuild it. We can assume
* that the current transaction has some lock on the rel already.
*/
RelationIncrementReferenceCount(relation);
RelationClearRelation(relation, true);
RelationDecrementReferenceCount(relation);
}
else
{
/*
* During abort processing, the current resource owner is not
* valid and we cannot hold a refcnt. Without a valid
* transaction, RelationClearRelation() would just mark the rel as
* invalid anyway, so we can do the same directly.
*/
RelationInvalidateRelation(relation);
}
}
else
{
/*
* Pre-existing rels can be dropped from the relcache if not open.