pg_upgrade: Preserve relfilenodes and tablespace OIDs.

Currently, database OIDs, relfilenodes, and tablespace OIDs can all
change when a cluster is upgraded using pg_upgrade. It seems better
to preserve them, because (1) it makes troubleshooting pg_upgrade
easier, since you don't have to do a lot of work to match up files
in the old and new clusters, (2) it allows 'rsync' to save bandwidth
when used to re-sync a cluster after an upgrade, and (3) if we ever
encrypt or sign blocks, we would likely want to use a nonce that
depends on these values.

This patch only arranges to preserve relfilenodes and tablespace
OIDs. The task of preserving database OIDs is left for another patch,
since it involves some complexities that don't exist in these cases.

Database OIDs have a similar issue, but there are some tricky points
in that case that do not apply to these cases, so that problem is left
for another patch.

Shruthi KC, based on an earlier patch from Antonin Houska, reviewed
and with some adjustments by me.

Discussion: http://postgr.es/m/CA+TgmoYgTwYcUmB=e8+hRHOFA0kkS6Kde85+UNdon6q7bt1niQ@mail.gmail.com

Author: robertmhaas

src/backend/bootstrap/bootparse.y

@@ -212,7 +212,8 @@ Boot_CreateStmt:
 												   mapped_relation,
 												   true,
 												   &relfrozenxid,
-												   &relminmxid);
+												   &relminmxid,
+												   true);
 						elog(DEBUG4, "bootstrap relation created");
 					}
 					else

src/backend/catalog/heap.c

@@ -91,7 +91,9 @@
 
 /* Potentially set by pg_upgrade_support functions */
 Oid			binary_upgrade_next_heap_pg_class_oid = InvalidOid;
+Oid			binary_upgrade_next_heap_pg_class_relfilenode = InvalidOid;
 Oid			binary_upgrade_next_toast_pg_class_oid = InvalidOid;
+Oid			binary_upgrade_next_toast_pg_class_relfilenode = InvalidOid;
 
 static void AddNewRelationTuple(Relation pg_class_desc,
 								Relation new_rel_desc,
@@ -285,8 +287,12 @@ SystemAttributeByName(const char *attname)
  *		heap_create		- Create an uncataloged heap relation
  *
  *		Note API change: the caller must now always provide the OID
- *		to use for the relation.  The relfilenode may (and, normally,
- *		should) be left unspecified.
+ *		to use for the relation.  The relfilenode may be (and in
+ *		the simplest cases is) left unspecified.
+ *
+ *		create_storage indicates whether or not to create the storage.
+ *		However, even if create_storage is true, no storage will be
+ *		created if the relkind is one that doesn't have storage.
  *
  *		rel->rd_rel is initialized by RelationBuildLocalRelation,
  *		and is mostly zeroes at return.
@@ -306,9 +312,9 @@ heap_create(const char *relname,
 			bool mapped_relation,
 			bool allow_system_table_mods,
 			TransactionId *relfrozenxid,
-			MultiXactId *relminmxid)
+			MultiXactId *relminmxid,
+			bool create_storage)
 {
-	bool		create_storage;
 	Relation	rel;
 
 	/* The caller must have provided an OID for the relation. */
@@ -343,17 +349,17 @@ heap_create(const char *relname,
 	if (!RELKIND_HAS_TABLESPACE(relkind))
 		reltablespace = InvalidOid;
 
-	/*
-	 * Decide whether to create storage. If caller passed a valid relfilenode,
-	 * storage is already created, so don't do it here.  Also don't create it
-	 * for relkinds without physical storage.
-	 */
-	if (!RELKIND_HAS_STORAGE(relkind) || OidIsValid(relfilenode))
+	/* Don't create storage for relkinds without physical storage. */
+	if (!RELKIND_HAS_STORAGE(relkind))
 		create_storage = false;
 	else
 	{
-		create_storage = true;
-		relfilenode = relid;
+		/*
+		 * If relfilenode is unspecified by the caller then create storage
+		 * with oid same as relid.
+		 */
+		if (!OidIsValid(relfilenode))
+			relfilenode = relid;
 	}
 
 	/*
@@ -1121,6 +1127,9 @@ heap_create_with_catalog(const char *relname,
 	Oid			existing_relid;
 	Oid			old_type_oid;
 	Oid			new_type_oid;
+
+	/* By default set to InvalidOid unless overridden by binary-upgrade */
+	Oid			relfilenode = InvalidOid;
 	TransactionId relfrozenxid;
 	MultiXactId relminmxid;
 
@@ -1183,7 +1192,7 @@ heap_create_with_catalog(const char *relname,
 	 */
 	if (!OidIsValid(relid))
 	{
-		/* Use binary-upgrade override for pg_class.oid/relfilenode? */
+		/* Use binary-upgrade override for pg_class.oid and relfilenode */
 		if (IsBinaryUpgrade)
 		{
 			/*
@@ -1200,6 +1209,14 @@ heap_create_with_catalog(const char *relname,
 				{
 					relid = binary_upgrade_next_toast_pg_class_oid;
 					binary_upgrade_next_toast_pg_class_oid = InvalidOid;
+
+					if (!OidIsValid(binary_upgrade_next_toast_pg_class_relfilenode))
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+								  errmsg("toast relfilenode value not set when in binary upgrade mode")));
+
+					relfilenode = binary_upgrade_next_toast_pg_class_relfilenode;
+					binary_upgrade_next_toast_pg_class_relfilenode = InvalidOid;
 				}
 			}
 			else
@@ -1211,6 +1228,17 @@ heap_create_with_catalog(const char *relname,
 
 				relid = binary_upgrade_next_heap_pg_class_oid;
 				binary_upgrade_next_heap_pg_class_oid = InvalidOid;
+
+				if (RELKIND_HAS_STORAGE(relkind))
+				{
+					if (!OidIsValid(binary_upgrade_next_heap_pg_class_relfilenode))
+						ereport(ERROR,
+								(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+								 errmsg("relfilenode value not set when in binary upgrade mode")));
+
+					relfilenode = binary_upgrade_next_heap_pg_class_relfilenode;
+					binary_upgrade_next_heap_pg_class_relfilenode = InvalidOid;
+				}
 			}
 		}
 
@@ -1250,12 +1278,16 @@ heap_create_with_catalog(const char *relname,
 	 * Create the relcache entry (mostly dummy at this point) and the physical
 	 * disk file.  (If we fail further down, it's the smgr's responsibility to
 	 * remove the disk file again.)
+	 *
+	 * NB: Note that passing create_storage = true is correct even for binary
+	 * upgrade.  The storage we create here will be replaced later, but we need
+	 * to have something on disk in the meanwhile.
 	 */
 	new_rel_desc = heap_create(relname,
 							   relnamespace,
 							   reltablespace,
 							   relid,
-							   InvalidOid,
+							   relfilenode,
 							   accessmtd,
 							   tupdesc,
 							   relkind,
@@ -1264,7 +1296,8 @@ heap_create_with_catalog(const char *relname,
 							   mapped_relation,
 							   allow_system_table_mods,
 							   &relfrozenxid,
-							   &relminmxid);
+							   &relminmxid,
+							   true);
 
 	Assert(relid == RelationGetRelid(new_rel_desc));
 

src/backend/catalog/index.c

@@ -87,6 +87,7 @@
 
 /* Potentially set by pg_upgrade_support functions */
 Oid			binary_upgrade_next_index_pg_class_oid = InvalidOid;
+Oid			binary_upgrade_next_index_pg_class_relfilenode = InvalidOid;
 
 /*
  * Pointer-free representation of variables used when reindexing system
@@ -733,6 +734,7 @@ index_create(Relation heapRelation,
 	char		relkind;
 	TransactionId relfrozenxid;
 	MultiXactId relminmxid;
+	bool		create_storage = !OidIsValid(relFileNode);
 
 	/* constraint flags can only be set when a constraint is requested */
 	Assert((constr_flags == 0) ||
@@ -904,7 +906,7 @@ index_create(Relation heapRelation,
 	 */
 	if (!OidIsValid(indexRelationId))
 	{
-		/* Use binary-upgrade override for pg_class.oid/relfilenode? */
+		/* Use binary-upgrade override for pg_class.oid and relfilenode */
 		if (IsBinaryUpgrade)
 		{
 			if (!OidIsValid(binary_upgrade_next_index_pg_class_oid))
@@ -914,6 +916,22 @@ index_create(Relation heapRelation,
 
 			indexRelationId = binary_upgrade_next_index_pg_class_oid;
 			binary_upgrade_next_index_pg_class_oid = InvalidOid;
+
+			/* Overide the index relfilenode */
+			if ((relkind == RELKIND_INDEX) &&
+				(!OidIsValid(binary_upgrade_next_index_pg_class_relfilenode)))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("index relfilenode value not set when in binary upgrade mode")));
+			relFileNode = binary_upgrade_next_index_pg_class_relfilenode;
+			binary_upgrade_next_index_pg_class_relfilenode = InvalidOid;
+
+			/*
+			 * Note that we want create_storage = true for binary upgrade.
+			 * The storage we create here will be replaced later, but we need
+			 * to have something on disk in the meanwhile.
+			 */
+			Assert(create_storage);
 		}
 		else
 		{
@@ -940,7 +958,8 @@ index_create(Relation heapRelation,
 								mapped_relation,
 								allow_system_table_mods,
 								&relfrozenxid,
-								&relminmxid);
+								&relminmxid,
+								create_storage);
 
 	Assert(relfrozenxid == InvalidTransactionId);
 	Assert(relminmxid == InvalidMultiXactId);

src/backend/commands/tablespace.c

@@ -89,6 +89,7 @@ char	   *default_tablespace = NULL;
 char	   *temp_tablespaces = NULL;
 bool		allow_in_place_tablespaces = false;
 
+Oid         binary_upgrade_next_pg_tablespace_oid = InvalidOid;
 
 static void create_tablespace_directories(const char *location,
 										  const Oid tablespaceoid);
@@ -340,8 +341,20 @@ CreateTableSpace(CreateTableSpaceStmt *stmt)
 
 	MemSet(nulls, false, sizeof(nulls));
 
-	tablespaceoid = GetNewOidWithIndex(rel, TablespaceOidIndexId,
-									   Anum_pg_tablespace_oid);
+	if (IsBinaryUpgrade)
+	{
+		/* Use binary-upgrade override for tablespace oid */
+		if (!OidIsValid(binary_upgrade_next_pg_tablespace_oid))
+			ereport(ERROR,
+					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+					 errmsg("pg_tablespace OID value not set when in binary upgrade mode")));
+
+		tablespaceoid = binary_upgrade_next_pg_tablespace_oid;
+		binary_upgrade_next_pg_tablespace_oid = InvalidOid;
+	}
+	else
+		tablespaceoid = GetNewOidWithIndex(rel, TablespaceOidIndexId,
+										   Anum_pg_tablespace_oid);
 	values[Anum_pg_tablespace_oid - 1] = ObjectIdGetDatum(tablespaceoid);
 	values[Anum_pg_tablespace_spcname - 1] =
 		DirectFunctionCall1(namein, CStringGetDatum(stmt->tablespacename));

src/backend/utils/adt/pg_upgrade_support.c

@@ -29,6 +29,17 @@ do {															\
 				 errmsg("function can only be called when server is in binary upgrade mode"))); \
 } while (0)
 
+Datum
+binary_upgrade_set_next_pg_tablespace_oid(PG_FUNCTION_ARGS)
+{
+	Oid			tbspoid = PG_GETARG_OID(0);
+
+	CHECK_IS_BINARY_UPGRADE;
+	binary_upgrade_next_pg_tablespace_oid = tbspoid;
+
+	PG_RETURN_VOID();
+}
+
 Datum
 binary_upgrade_set_next_pg_type_oid(PG_FUNCTION_ARGS)
 {
@@ -84,6 +95,17 @@ binary_upgrade_set_next_heap_pg_class_oid(PG_FUNCTION_ARGS)
 	PG_RETURN_VOID();
 }
 
+Datum
+binary_upgrade_set_next_heap_relfilenode(PG_FUNCTION_ARGS)
+{
+	Oid			nodeoid = PG_GETARG_OID(0);
+
+	CHECK_IS_BINARY_UPGRADE;
+	binary_upgrade_next_heap_pg_class_relfilenode = nodeoid;
+
+	PG_RETURN_VOID();
+}
+
 Datum
 binary_upgrade_set_next_index_pg_class_oid(PG_FUNCTION_ARGS)
 {
@@ -95,6 +117,17 @@ binary_upgrade_set_next_index_pg_class_oid(PG_FUNCTION_ARGS)
 	PG_RETURN_VOID();
 }
 
+Datum
+binary_upgrade_set_next_index_relfilenode(PG_FUNCTION_ARGS)
+{
+	Oid			nodeoid = PG_GETARG_OID(0);
+
+	CHECK_IS_BINARY_UPGRADE;
+	binary_upgrade_next_index_pg_class_relfilenode = nodeoid;
+
+	PG_RETURN_VOID();
+}
+
 Datum
 binary_upgrade_set_next_toast_pg_class_oid(PG_FUNCTION_ARGS)
 {
@@ -106,6 +139,17 @@ binary_upgrade_set_next_toast_pg_class_oid(PG_FUNCTION_ARGS)
 	PG_RETURN_VOID();
 }
 
+Datum
+binary_upgrade_set_next_toast_relfilenode(PG_FUNCTION_ARGS)
+{
+	Oid			nodeoid = PG_GETARG_OID(0);
+
+	CHECK_IS_BINARY_UPGRADE;
+	binary_upgrade_next_toast_pg_class_relfilenode = nodeoid;
+
+	PG_RETURN_VOID();
+}
+
 Datum
 binary_upgrade_set_next_pg_enum_oid(PG_FUNCTION_ARGS)
 {