diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 61816730955..db3eb2cce1e 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -1002,7 +1002,7 @@ ExtendBufferedRelTo(BufferManagerRelation bmr,
 	if (buffer == InvalidBuffer)
 	{
 		Assert(extended_by == 0);
-		buffer = ReadBuffer_common(bmr.rel, bmr.smgr, 0,
+		buffer = ReadBuffer_common(bmr.rel, bmr.smgr, bmr.relpersistence,
 								   fork, extend_to - 1, mode, strategy);
 	}
 
@@ -1117,16 +1117,8 @@ PinBufferForBlock(Relation rel,
 
 	Assert(blockNum != P_NEW);
 
-	/*
-	 * If there is no Relation it usually implies recovery and thus permanent,
-	 * but we take an argument because CreateAndCopyRelationData can reach us
-	 * with only an SMgrRelation for an unlogged relation that we don't want
-	 * to flag with BM_PERMANENT.
-	 */
 	if (rel)
 		persistence = rel->rd_rel->relpersistence;
-	else if (smgr_persistence == 0)
-		persistence = RELPERSISTENCE_PERMANENT;
 	else
 		persistence = smgr_persistence;
 
diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h
index a1e71013d32..bc26a4536ff 100644
--- a/src/include/storage/bufmgr.h
+++ b/src/include/storage/bufmgr.h
@@ -114,14 +114,10 @@ typedef struct BufferManagerRelation
 
 struct ReadBuffersOperation
 {
-	/*
-	 * The following members should be set by the caller.  If only smgr is
-	 * provided without rel, then smgr_persistence can be set to override the
-	 * default assumption of RELPERSISTENCE_PERMANENT.
-	 */
-	Relation	rel;
+	/* The following members should be set by the caller. */
+	Relation	rel;			/* optional */
 	struct SMgrRelationData *smgr;
-	char		smgr_persistence;
+	char		smgr_persistence;	/* optional if rel != NULL */
 	ForkNumber	forknum;
 	BufferAccessStrategy strategy;