Horton

Re: race condition in pg_class

Noah Misch <noah@leadboat.com>

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From: Noah Misch <noah@leadboat.com>
To: Alexander Lakhin <exclusion@gmail.com>
Cc: Nitin Motiani <nitinmotiani@google.com>, Heikki Linnakangas <hlinnaka@iki.fi>, Robert Haas <robertmhaas@gmail.com>, pgsql-hackers@postgresql.org, Tom Lane <tgl@sss.pgh.pa.us>, Smolkin Grigory <smallkeen@gmail.com>, Michael Paquier <michael@paquier.xyz>
Date: 2024-10-22T03:52:15Z
Lists: pgsql-hackers

Commits

Same data as JSON: GET /api/v1/messages/:b64id/commits the thread's linked commits as JSON, with link sources. API reference →

  1. Replace tests of ALTER DATABASE RESET TABLESPACE.

  2. meson: Flush stdout in testwrap

  3. Fix catcache invalidation of a list entry that's being built

  4. Stop reading uninitialized memory in heap_inplace_lock().

  5. Fix use of uninitialized value in previous commit.

  6. Back-patch "Refactor code in tablecmds.c to check and process tablespace moves"

  7. Fix data loss at inplace update after heap_update().

  8. For inplace update durability, make heap_update() callers wait.

  9. Warn if LOCKTAG_TUPLE is held at commit, under debug_assertions.

  10. Don't lose partitioned table reltuples=0 after relhassubclass=f.

  11. Fix new assertion for MERGE view_name ... DO NOTHING.

  12. Remove configuration-dependent output from new inplace-inval test.

  13. AccessExclusiveLock new relations just after assigning the OID.

  14. Cope with inplace update making catcache stale during TOAST fetch.

  15. Expand comments and add an assertion in nodeModifyTable.c.

  16. Improve test coverage for changes to inplace-updated catalogs.

  17. Lock before setting relhassubclass on RELKIND_PARTITIONED_INDEX.

  18. Lock owned sequences during ALTER TABLE SET { LOGGED | UNLOGGED }.

  19. Make TAP todo_start effects the same under Meson and prove_check.

  20. Add an injection_points isolation test suite.

  21. Add wait event type "InjectionPoint", a custom type like "Extension".

  22. Create waitfuncs.c for pg_isolation_test_session_is_blocked().

  23. Rework planning and execution of UPDATE and DELETE.

Attachments

On Mon, Oct 21, 2024 at 10:00:00PM +0300, Alexander Lakhin wrote:
> Please look at an anomaly introduced with a07e03fd8.
> With the attached modification for intra-grant-inplace.spec, running this
> test triggers a Valgrind-detected error for me:
> ==00:00:00:09.624 319033== Conditional jump or move depends on uninitialised value(s)
> ==00:00:00:09.624 319033==    at 0x25D120: DoesMultiXactIdConflict (heapam.c:7373)
> ==00:00:00:09.624 319033==    by 0x25B45A: heap_inplace_lock (heapam.c:6265)
> ==00:00:00:09.624 319033==    by 0x27D8CB: systable_inplace_update_begin (genam.c:867)
> ==00:00:00:09.624 319033==    by 0x33F717: index_update_stats (index.c:2856)
> ==00:00:00:09.624 319033==    by 0x33FEE2: index_build (index.c:3106)
> ==00:00:00:09.625 319033==    by 0x33C7D3: index_create (index.c:1276)
> ==00:00:00:09.625 319033==    by 0x451000: DefineIndex (indexcmds.c:1216)
> ==00:00:00:09.625 319033==    by 0x48D091: ATExecAddIndex (tablecmds.c:9156)
> ==00:00:00:09.625 319033==    by 0x483F8E: ATExecCmd (tablecmds.c:5302)
> ==00:00:00:09.625 319033==    by 0x483877: ATRewriteCatalogs (tablecmds.c:5186)
> ==00:00:00:09.625 319033==    by 0x482B9A: ATController (tablecmds.c:4741)
> ==00:00:00:09.625 319033==    by 0x4827A1: AlterTable (tablecmds.c:4387)
> ==00:00:00:09.625 319033==

Thanks.

> Perhaps current_is_member in heap_inplace_lock() should be initialized
> before the DoesMultiXactIdConflict() call as in other places...

heap_inplace_lock() ignores current_is_member after computing it, so let's
just pass NULL, as attached.