On 19/06/2024 23:00, Alexander Lakhin wrote:
Please look at a new anomaly, that I've discovered in master.
...
triggers a segfault:
2024-06-19 19:22:49.009 UTC [1607210:6] LOG: server process (PID 1607671) was
terminated by signal 11: Segmentation fault
...
server.log might also contain:
2024-06-19 19:25:38.060 UTC [1618682:5] psql ERROR: could not read blocks 3..3 in file
"base/28531/28840": read only 0
of 8192 bytes
Thanks for the report! I was not able to reproduce the segfault, but I
do see the "could not read blocks" error very quickly with the script.
In commit af0e7deb4a, I removed the call to RelationCloseSmgr() from
RelationCacheInvalidate(). I thought it was no longer needed, because we
no longer free the underlying SmgrRelation.
However, it meant that if the relfilenode of the relation was changed,
the relation keeps pointing to the SMgrRelation of the old relfilenode.
So we still need the RelationCloseSmgr() call, in case the relfilenode
has changed.
Per attached patch.
--
Heikki Linnakangas
Neon (https://neon.tech)
From 17a1e68a636edd87a34acf34dace2a696af81a2d Mon Sep 17 00:00:00 2001
From: Heikki Linnakangas <heikki.linnakan...@iki.fi>
Date: Fri, 21 Jun 2024 01:45:53 +0300
Subject: [PATCH 1/1] Fix relcache invalidation when relfilelocator is updated
In commit af0e7deb4a, I removed this call to RelationCloseSmgr(),
because the dangling SMgrRelation was no longer an issue. However, we
still need to call in case the relation's relfilelocator has changed,
so that we open the new relfile on the next access.
Reported-by: Alexander Lakhin <exclus...@gmail.com>
Discussion: https://www.postgresql.org/message-id/987b1c8c-8c91-4847-ca0e-879f421680ff%40gmail.com
---
src/backend/utils/cache/relcache.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index 35dbb87ae3..f45880d96d 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -3032,6 +3032,9 @@ RelationCacheInvalidate(bool debug_discard)
{
relation = idhentry->reldesc;
+ /* Close all smgr references, in case the relfilelocator has changed */
+ RelationCloseSmgr(relation);
+
/*
* Ignore new relations; no other backend will manipulate them before
* we commit. Likewise, before replacing a relation's relfilelocator,
--
2.39.2
