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.

2 files changed, 7 insertions, 0 deletions

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 dba19ebc6d3..ff92360155d 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);
 }