Move TablespaceCreateDbspace() call into smgrcreate(), which is where it

probably should have been to begin with; this is to cover cases like
needing to recreate the per-db directory during WAL replay.
Also, fix heap_create to force pg_class.reltablespace to be zero instead
of the database's default tablespace; this makes the world safe for
CREATE DATABASE to handle all tables in the default tablespace alike,
as per previous discussion.  And force pg_class.reltablespace to zero
when creating a relation without physical storage (eg, a view); this
avoids possibly having dangling references in this column after a
subsequent DROP TABLESPACE.

src/backend/catalog/heap.c

@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.271 2004/06/18 06:13:19 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/catalog/heap.c,v 1.272 2004/07/11 19:52:48 tgl Exp $
  *
  *
  * INTERFACE ROUTINES
@@ -43,7 +43,6 @@
 #include "catalog/pg_statistic.h"
 #include "catalog/pg_type.h"
 #include "commands/tablecmds.h"
-#include "commands/tablespace.h"
 #include "commands/trigger.h"
 #include "miscadmin.h"
 #include "nodes/makefuncs.h"
@@ -195,10 +194,6 @@ SystemAttributeByName(const char *attname, bool relhasoids)
  *		and is mostly zeroes at return.
  *
  *		Remove the system relation specific code to elsewhere eventually.
- *
- * If storage_create is TRUE then heap_storage_create is called here,
- * else caller must call heap_storage_create later (or not at all,
- * if the relation doesn't need physical storage).
  * ----------------------------------------------------------------
  */
 Relation
@@ -207,7 +202,7 @@ heap_create(const char *relname,
 			Oid reltablespace,
 			TupleDesc tupDesc,
 			bool shared_relation,
-			bool storage_create,
+			bool create_storage,
 			bool allow_system_table_mods)
 {
 	Oid			relid;
@@ -268,6 +263,25 @@ heap_create(const char *relname,
 	else
 		relid = newoid();
 
+	/*
+	 * Never allow a pg_class entry to explicitly specify the database's
+	 * default tablespace in reltablespace; force it to zero instead.
+	 * This ensures that if the database is cloned with a different
+	 * default tablespace, the pg_class entry will still match where
+	 * CREATE DATABASE will put the physically copied relation.
+	 *
+	 * Yes, this is a bit of a hack.
+	 */
+	if (reltablespace == MyDatabaseTableSpace)
+		reltablespace = InvalidOid;
+
+	/*
+	 * Also, force reltablespace to zero if the relation has no physical
+	 * storage.  This is mainly just for cleanliness' sake.
+	 */
+	if (!create_storage)
+		reltablespace = InvalidOid;
+
 	/*
 	 * build the relcache entry.
 	 */
@@ -280,33 +294,18 @@ heap_create(const char *relname,
 									 nailme);
 
 	/*
-	 * have the storage manager create the relation's disk file, if
+	 * have the storage manager create the relation's disk file, if needed.
-	 * wanted.
 	 */
-	if (storage_create)
+	if (create_storage)
-		heap_storage_create(rel);
+	{
+		Assert(rel->rd_smgr == NULL);
+		rel->rd_smgr = smgropen(rel->rd_node);
+		smgrcreate(rel->rd_smgr, rel->rd_istemp, false);
+	}
 
 	return rel;
 }
 
-void
-heap_storage_create(Relation rel)
-{
-	/*
-	 * We may be using the target table space for the first time in this
-	 * database, so create a per-database subdirectory if needed.
-	 *
-	 * XXX it might be better to do this right in smgrcreate...
-	 */
-	TablespaceCreateDbspace(rel->rd_node.spcNode, rel->rd_node.dbNode);
-	/*
-	 * Now we can make the file.
-	 */
-	Assert(rel->rd_smgr == NULL);
-	rel->rd_smgr = smgropen(rel->rd_node);
-	smgrcreate(rel->rd_smgr, rel->rd_istemp, false);
-}
-
 /* ----------------------------------------------------------------
  *		heap_create_with_catalog		- Create a cataloged relation
  *

src/backend/commands/tablespace.c

@@ -45,7 +45,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.5 2004/07/02 18:59:22 joe Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/tablespace.c,v 1.6 2004/07/11 19:52:49 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -85,9 +85,13 @@ static bool directory_is_empty(const char *path);
  *
  * If tablespaces are not supported, this is just a no-op; CREATE DATABASE
  * is expected to create the default subdirectory for the database.
+ *
+ * isRedo indicates that we are creating an object during WAL replay;
+ * we can skip doing locking in that case (and should do so to avoid
+ * any possible problems with pg_tablespace not being valid).
  */
 void
-TablespaceCreateDbspace(Oid spcNode, Oid dbNode)
+TablespaceCreateDbspace(Oid spcNode, Oid dbNode, bool isRedo)
 {
 #ifdef HAVE_SYMLINK
 	struct stat st;
@@ -116,7 +120,10 @@ TablespaceCreateDbspace(Oid spcNode, Oid dbNode)
 			 */
 			Relation rel;
 
-			rel = heap_openr(TableSpaceRelationName, ExclusiveLock);
+			if (!isRedo)
+				rel = heap_openr(TableSpaceRelationName, ExclusiveLock);
+			else
+				rel = NULL;
 
 			/*
 			 * Recheck to see if someone created the directory while
@@ -137,7 +144,8 @@ TablespaceCreateDbspace(Oid spcNode, Oid dbNode)
 			}
 
 			/* OK to drop the exclusive lock */
-			heap_close(rel, ExclusiveLock);
+			if (!isRedo)
+				heap_close(rel, ExclusiveLock);
 		}
 		else
 		{

src/backend/storage/smgr/smgr.c

@@ -11,12 +11,13 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.75 2004/07/01 00:51:07 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/storage/smgr/smgr.c,v 1.76 2004/07/11 19:52:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
 #include "postgres.h"
 
+#include "commands/tablespace.h"
 #include "storage/bufmgr.h"
 #include "storage/freespace.h"
 #include "storage/ipc.h"
@@ -309,6 +310,19 @@ smgrcreate(SMgrRelation reln, bool isTemp, bool isRedo)
 	PendingRelDelete *pending;
 	MemoryContext	old_cxt;
 
+	/*
+	 * We may be using the target table space for the first time in this
+	 * database, so create a per-database subdirectory if needed.
+	 *
+	 * XXX this is a fairly ugly violation of module layering, but this seems
+	 * to be the best place to put the check.  Maybe TablespaceCreateDbspace
+	 * should be here and not in commands/tablespace.c?  But that would imply
+	 * importing a lot of stuff that smgr.c oughtn't know, either.
+	 */
+	TablespaceCreateDbspace(reln->smgr_rnode.spcNode,
+							reln->smgr_rnode.dbNode,
+							isRedo);
+
 	if (! (*(smgrsw[reln->smgr_which].smgr_create)) (reln, isRedo))
 		ereport(ERROR,
 				(errcode_for_file_access(),

src/include/catalog/heap.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/catalog/heap.h,v 1.67 2004/06/18 06:14:05 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/catalog/heap.h,v 1.68 2004/07/11 19:52:51 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -40,11 +40,9 @@ extern Relation heap_create(const char *relname,
 			Oid reltablespace,
 			TupleDesc tupDesc,
 			bool shared_relation,
-			bool storage_create,
+			bool create_storage,
 			bool allow_system_table_mods);
 
-extern void heap_storage_create(Relation rel);
-
 extern Oid heap_create_with_catalog(const char *relname,
 						 Oid relnamespace,
 						 Oid reltablespace,

src/include/commands/tablespace.h

@@ -7,7 +7,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/commands/tablespace.h,v 1.2 2004/06/25 21:55:58 tgl Exp $
+ * $PostgreSQL: pgsql/src/include/commands/tablespace.h,v 1.3 2004/07/11 19:52:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -20,7 +20,7 @@ extern void CreateTableSpace(CreateTableSpaceStmt *stmt);
 
 extern void DropTableSpace(DropTableSpaceStmt *stmt);
 
-extern void TablespaceCreateDbspace(Oid spcNode, Oid dbNode);
+extern void TablespaceCreateDbspace(Oid spcNode, Oid dbNode, bool isRedo);
 
 extern Oid	get_tablespace_oid(const char *tablespacename);