From eb5ad4ff05fd382ac98cab60b82f7fd6ce4cfeb8 Mon Sep 17 00:00:00 2001 From: Peter Geoghegan Date: Tue, 3 Jan 2023 21:48:27 -0800 Subject: [PATCH] Check that xmax didn't commit in freeze check. We cannot rely on TransactionIdDidAbort here, since in general it may report transactions that were in-progress at the time of an earlier hard crash as not aborted, effectively behaving as if they were still in progress even after crash recovery completes. Go back to defensively verifying that xmax didn't commit instead. Oversight in commit 79d4bf4e. Author: Peter Geoghegan Reported-By: Andres Freund Discussion: https://postgr.es/m/20230104035636.hy5djyr2as4gbc4q@awork3.anarazel.de --- src/backend/access/heap/heapam.c | 14 ++++++++++---- 1 file changed, 10 insertions(+), 4 deletions(-) diff --git a/src/backend/access/heap/heapam.c b/src/backend/access/heap/heapam.c index bad2a89e4f..63c4f01f0f 100644 --- a/src/backend/access/heap/heapam.c +++ b/src/backend/access/heap/heapam.c @@ -6208,10 +6208,10 @@ FreezeMultiXactId(MultiXactId multi, uint16 t_infomask, * been pruned away instead, since updater XID is < OldestXmin). * Just remove xmax. */ - if (!TransactionIdDidAbort(update_xact)) + if (TransactionIdDidCommit(update_xact)) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), - errmsg_internal("multixact %u contains non-aborted update XID %u from before removable cutoff %u", + errmsg_internal("multixact %u contains committed update XID %u from before removable cutoff %u", multi, update_xact, cutoffs->OldestXmin))); *flags |= FRM_INVALIDATE_XMAX; @@ -6825,15 +6825,21 @@ heap_freeze_execute_prepared(Relation rel, Buffer buffer, errmsg_internal("uncommitted xmin %u needs to be frozen", xmin))); } + + /* + * TransactionIdDidAbort won't work reliably in the presence of XIDs + * left behind by transactions that were in progress during a crash, + * so we can only check that xmax didn't commit + */ if (frz->checkflags & HEAP_FREEZE_CHECK_XMAX_ABORTED) { TransactionId xmax = HeapTupleHeaderGetRawXmax(htup); Assert(TransactionIdIsNormal(xmax)); - if (unlikely(!TransactionIdDidAbort(xmax))) + if (unlikely(TransactionIdDidCommit(xmax))) ereport(ERROR, (errcode(ERRCODE_DATA_CORRUPTED), - errmsg_internal("cannot freeze non-aborted xmax %u", + errmsg_internal("cannot freeze committed xmax %u", xmax))); } }