Make sure that open hash table scans are cleaned up when bgwriter tries to

recover from elog(ERROR).  Problem was created by introduction of hash seq
search tracking awhile back, and affects all branches that have bgwriter;
in HEAD the disease has snuck into autovacuum and walwriter too.  (Not sure
that the latter two use hash_seq_search at the moment, but surely they might
someday.)  Per report from Sergey Koposov.

3 files changed, 9 insertions, 3 deletions

diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index 7b6da97b57..2a6e654269 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -55,7 +55,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.56 2007/08/02 23:39:44 adunstan Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/autovacuum.c,v 1.57 2007/09/11 17:15:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -472,6 +472,7 @@ AutoVacLauncherMain(int argc, char *argv[])
 		 */
 		LWLockReleaseAll();
 		AtEOXact_Files();
+		AtEOXact_HashTables(false);
 
 		/*
 		 * Now return to normal top-level context and clear ErrorContext for
diff --git a/src/backend/postmaster/bgwriter.c b/src/backend/postmaster/bgwriter.c
index d8c7c3aa13..81f48c01fb 100644
--- a/src/backend/postmaster/bgwriter.c
+++ b/src/backend/postmaster/bgwriter.c
@@ -37,7 +37,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.41 2007/07/03 14:51:24 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/bgwriter.c,v 1.42 2007/09/11 17:15:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -295,6 +295,7 @@ BackgroundWriterMain(void)
 		/* we needn't bother with the other ResourceOwnerRelease phases */
 		AtEOXact_Buffers(false);
 		AtEOXact_Files();
+		AtEOXact_HashTables(false);
 
 		/* Warn any waiting backends that the checkpoint failed. */
 		if (ckpt_active)
diff --git a/src/backend/postmaster/walwriter.c b/src/backend/postmaster/walwriter.c
index b4d594661a..d5736b7e69 100644
--- a/src/backend/postmaster/walwriter.c
+++ b/src/backend/postmaster/walwriter.c
@@ -34,7 +34,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/postmaster/walwriter.c,v 1.1 2007/07/24 04:54:09 tgl Exp $
+ *	  $PostgreSQL: pgsql/src/backend/postmaster/walwriter.c,v 1.2 2007/09/11 17:15:33 tgl Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -50,11 +50,13 @@
 #include "miscadmin.h"
 #include "postmaster/walwriter.h"
 #include "storage/bufmgr.h"
+#include "storage/fd.h"
 #include "storage/ipc.h"
 #include "storage/lwlock.h"
 #include "storage/pmsignal.h"
 #include "storage/smgr.h"
 #include "utils/guc.h"
+#include "utils/hsearch.h"
 #include "utils/memutils.h"
 #include "utils/resowner.h"
 
@@ -179,6 +181,8 @@ WalWriterMain(void)
 							 false, true);
 		/* we needn't bother with the other ResourceOwnerRelease phases */
 		AtEOXact_Buffers(false);
+		AtEOXact_Files();
+		AtEOXact_HashTables(false);
 
 		/*
 		 * Now return to normal top-level context and clear ErrorContext for