From 9ab2734d2b2246db3ca16e06ec560ad0a33621e9 Mon Sep 17 00:00:00 2001 From: Jim Jones Date: Wed, 4 Nov 2026 07:24:12 +0100 Subject: [PATCH v4 6/6] pg_freespacemap: Reject relations whose free space map cannot be read pg_freespace() returned 0 for unlogged relations during recovery and for temporary tables of other sessions without a free space map fork, because a missing free space map reads as no free space. Report an error instead. Author: Surya Poondla Reviewed-by: Jim Jones --- contrib/pg_freespacemap/pg_freespacemap.c | 17 +++++++++++++++++ 1 file changed, 17 insertions(+) diff --git a/contrib/pg_freespacemap/pg_freespacemap.c b/contrib/pg_freespacemap/pg_freespacemap.c index 610fc90b5ba..4952468695d 100644 --- a/contrib/pg_freespacemap/pg_freespacemap.c +++ b/contrib/pg_freespacemap/pg_freespacemap.c @@ -9,6 +9,7 @@ #include "postgres.h" #include "access/relation.h" +#include "access/xlog.h" #include "fmgr.h" #include "storage/freespace.h" #include "utils/rel.h" @@ -41,6 +42,22 @@ pg_freespace(PG_FUNCTION_ARGS) RelationGetRelationName(rel)), errdetail_relkind_not_supported(rel->rd_rel->relkind))); + /* + * Reject attempts to read non-local temporary relations; we would be + * likely to get wrong data since we have no visibility into the owning + * session's local buffers. + */ + if (RELATION_IS_OTHER_TEMP(rel)) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary tables of other sessions"))); + + /* Temporary and unlogged relations are inaccessible during recovery. */ + if (!RelationIsPermanent(rel) && RecoveryInProgress()) + ereport(ERROR, + (errcode(ERRCODE_FEATURE_NOT_SUPPORTED), + errmsg("cannot access temporary or unlogged relations during recovery"))); + if (blkno < 0 || blkno > MaxBlockNumber) ereport(ERROR, (errcode(ERRCODE_INVALID_PARAMETER_VALUE), -- 2.56.0