From ad9a274778d2d88c46b90309212b92ee7fdf9afe Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter_e@gmx.net>
Date: Thu, 1 Feb 2018 17:07:38 -0500
Subject: [PATCH] Fix crash when canceling parallel query
elog(FATAL) would end up calling PortalCleanup(), which would call
executor shutdown code, which could fail and crash, especially under
parallel query. This was introduced by
8561e4840c81f7e345be2df170839846814fa004, which did not want to mark an
active portal as failed by a normal transaction abort anymore. But we
do need to do that for an elog(FATAL) exit. Introduce a variable
shmem_exit_inprogress similar to the existing proc_exit_inprogress, so
we can tell whether we are in the FATAL exit scenario.
Reported-by: Andres Freund <andres@anarazel.de>
---
src/backend/storage/ipc/ipc.c | 7 +++++++
src/backend/utils/mmgr/portalmem.c | 8 ++++++++
src/include/storage/ipc.h | 1 +
3 files changed, 16 insertions(+)
diff --git a/src/backend/storage/ipc/ipc.c b/src/backend/storage/ipc/ipc.c
index 2de35efbd4f..726db7b7f1b 100644
--- a/src/backend/storage/ipc/ipc.c
+++ b/src/backend/storage/ipc/ipc.c
@@ -39,6 +39,11 @@
*/
bool proc_exit_inprogress = false;
+/*
+ * Set when shmem_exit() is in progress.
+ */
+bool shmem_exit_inprogress = false;
+
/*
* This flag tracks whether we've called atexit() in the current process
* (or in the parent postmaster).
@@ -214,6 +219,8 @@ proc_exit_prepare(int code)
void
shmem_exit(int code)
{
+ shmem_exit_inprogress = true;
+
/*
* Call before_shmem_exit callbacks.
*
diff --git a/src/backend/utils/mmgr/portalmem.c b/src/backend/utils/mmgr/portalmem.c
index f3f0add1d6d..75a6dde32b3 100644
--- a/src/backend/utils/mmgr/portalmem.c
+++ b/src/backend/utils/mmgr/portalmem.c
@@ -22,6 +22,7 @@
#include "catalog/pg_type.h"
#include "commands/portalcmds.h"
#include "miscadmin.h"
+#include "storage/ipc.h"
#include "utils/builtins.h"
#include "utils/memutils.h"
#include "utils/snapmgr.h"
@@ -757,6 +758,13 @@ AtAbort_Portals(void)
{
Portal portal = hentry->portal;
+ /*
+ * When elog(FATAL) is progress, we need to set the active portal to
+ * failed, so that PortalCleanup() doesn't run the executor shutdown.
+ */
+ if (portal->status == PORTAL_ACTIVE && shmem_exit_inprogress)
+ MarkPortalFailed(portal);
+
/*
* Do nothing else to cursors held over from a previous transaction.
*/
diff --git a/src/include/storage/ipc.h b/src/include/storage/ipc.h
index e934a83a1c9..6a05a89349c 100644
--- a/src/include/storage/ipc.h
+++ b/src/include/storage/ipc.h
@@ -63,6 +63,7 @@ typedef void (*shmem_startup_hook_type) (void);
/* ipc.c */
extern PGDLLIMPORT bool proc_exit_inprogress;
+extern PGDLLIMPORT bool shmem_exit_inprogress;
extern void proc_exit(int code) pg_attribute_noreturn();
extern void shmem_exit(int code);
--
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