From a3032b89ce8e8e325035e2858a2b58a92d6ede7c Mon Sep 17 00:00:00 2001 From: Andres Freund Date: Mon, 9 Jan 2023 11:24:37 -0800 Subject: [PATCH v3 3/6] wip: amcheck: Fix bugs relating to 64bit xids Discussion: https://postgr.es/m/20230108002923.cyoser3ttmt63bfn@awork3.anarazel.de --- contrib/amcheck/verify_heapam.c | 16 +++++++++++++++- 1 file changed, 15 insertions(+), 1 deletion(-) diff --git a/contrib/amcheck/verify_heapam.c b/contrib/amcheck/verify_heapam.c index 4fcfd6df72d..56a3b3e9974 100644 --- a/contrib/amcheck/verify_heapam.c +++ b/contrib/amcheck/verify_heapam.c @@ -1576,11 +1576,25 @@ FullTransactionIdFromXidAndCtx(TransactionId xid, const HeapCheckContext *ctx) { uint32 epoch; + Assert(TransactionIdIsValid(ctx->next_xid)); + Assert(FullTransactionIdIsValid(ctx->next_fxid)); + if (!TransactionIdIsNormal(xid)) return FullTransactionIdFromEpochAndXid(0, xid); epoch = EpochFromFullTransactionId(ctx->next_fxid); if (xid > ctx->next_xid) + { + /* + * FIXME, doubtful this is the best fix. + * + * Can't represent the 32bit xid as a 64bit xid, as it's before fxid + * 0. Represent it as an xid from the future instead. + */ + if (epoch == 0) + return FullTransactionIdFromEpochAndXid(0, xid); + epoch--; + } return FullTransactionIdFromEpochAndXid(epoch, xid); } @@ -1597,8 +1611,8 @@ update_cached_xid_range(HeapCheckContext *ctx) LWLockRelease(XidGenLock); /* And compute alternate versions of the same */ - ctx->oldest_fxid = FullTransactionIdFromXidAndCtx(ctx->oldest_xid, ctx); ctx->next_xid = XidFromFullTransactionId(ctx->next_fxid); + ctx->oldest_fxid = FullTransactionIdFromXidAndCtx(ctx->oldest_xid, ctx); } /* -- 2.38.0