From eb6e9b5ea4a5e733da705c053906f3aff47c9bf5 Mon Sep 17 00:00:00 2001
From: Robert Haas <rhaas@postgresql.org>
Date: Fri, 14 Sep 2012 09:35:07 -0400
Subject: [PATCH] Properly set relpersistence for fake relcache entries.

This can result in buffers failing to be properly flushed at
checkpoint time, leading to data loss.

Report, diagnosis, and patch by Jeff Davis.
---
 src/backend/access/transam/xlogutils.c | 5 +++++
 src/backend/storage/buffer/bufmgr.c    | 2 ++
 2 files changed, 7 insertions(+)

diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index 6ddcc59b37a..5676120a863 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -394,6 +394,8 @@ CreateFakeRelcacheEntry(RelFileNode rnode)
 	FakeRelCacheEntry fakeentry;
 	Relation	rel;
 
+	Assert(InRecovery);
+
 	/* Allocate the Relation struct and all related space in one block. */
 	fakeentry = palloc0(sizeof(FakeRelCacheEntryData));
 	rel = (Relation) fakeentry;
@@ -403,6 +405,9 @@ CreateFakeRelcacheEntry(RelFileNode rnode)
 	/* We will never be working with temp rels during recovery */
 	rel->rd_backend = InvalidBackendId;
 
+	/* It must be a permanent table if we're in recovery. */
+	rel->rd_rel->relpersistence = RELPERSISTENCE_PERMANENT;
+
 	/* We don't know the name of the relation; use relfilenode instead */
 	sprintf(RelationGetRelationName(rel), "%u", rnode.relNode);
 
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index a3bf9a4d44e..f1c29e9d4a8 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -271,6 +271,8 @@ ReadBufferWithoutRelcache(RelFileNode rnode, ForkNumber forkNum,
 
 	SMgrRelation smgr = smgropen(rnode, InvalidBackendId);
 
+	Assert(InRecovery);
+
 	return ReadBuffer_common(smgr, RELPERSISTENCE_PERMANENT, forkNum, blockNum,
 							 mode, strategy, &hit);
 }
-- 
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