Tweak smgrblindwrt per advice from Vadim: add parameter indicating

whether to do fsync or not, and if so (which should be seldom) just
do the fsync immediately.  This way we need not build data structures
in md.c/fd.c for blind writes.

src/backend/storage/smgr/smgr.c

@@ -11,7 +11,7 @@
  *
  *
  * IDENTIFICATION
- *	  $Header: /cvsroot/pgsql/src/backend/storage/smgr/smgr.c,v 1.33 2000/04/09 04:43:20 tgl Exp $
+ *	  $Header: /cvsroot/pgsql/src/backend/storage/smgr/smgr.c,v 1.34 2000/04/10 23:41:52 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -38,7 +38,8 @@ typedef struct f_smgr
 							   char *buffer);
 	int			(*smgr_blindwrt) (char *dbname, char *relname,
 								  Oid dbid, Oid relid,
-								  BlockNumber blkno, char *buffer);
+								  BlockNumber blkno, char *buffer,
+								  bool dofsync);
 	int			(*smgr_markdirty) (Relation reln, BlockNumber blkno);
 	int			(*smgr_blindmarkdirty) (char *dbname, char *relname,
 										Oid dbid, Oid relid,
@@ -293,7 +294,8 @@ smgrflush(int16 which, Relation reln, BlockNumber blocknum, char *buffer)
  *		this case, the buffer manager will call smgrblindwrt() with
  *		the name and OID of the database and the relation to which the
  *		buffer belongs.  Every storage manager must be able to force
- *		this page down to stable storage in this circumstance.
+ *		this page down to stable storage in this circumstance.  The
+ *		write should be synchronous if dofsync is true.
  */
 int
 smgrblindwrt(int16 which,
@@ -302,7 +304,8 @@ smgrblindwrt(int16 which,
 			 Oid dbid,
 			 Oid relid,
 			 BlockNumber blkno,
-			 char *buffer)
+			 char *buffer,
+			 bool dofsync)
 {
 	char	   *dbstr;
 	char	   *relstr;
@@ -313,7 +316,7 @@ smgrblindwrt(int16 which,
 	relstr = pstrdup(relname);
 
 	status = (*(smgrsw[which].smgr_blindwrt)) (dbstr, relstr, dbid, relid,
-											   blkno, buffer);
+											   blkno, buffer, dofsync);
 
 	if (status == SM_FAIL)
 		elog(ERROR, "cannot write block %d of %s [%s] blind",