commit 2326df869ee8516b8b1f0e01930946e9a63800b5
Author:     Alvaro Herrera <alvherre@alvh.no-ip.org>
AuthorDate: Mon Nov 23 15:56:23 2020 -0300
CommitDate: Mon Nov 23 15:57:28 2020 -0300

    autovacuum-centered workitem fix

diff --git a/src/backend/postmaster/autovacuum.c b/src/backend/postmaster/autovacuum.c
index aa5b97fbac..77c1401bc9 100644
--- a/src/backend/postmaster/autovacuum.c
+++ b/src/backend/postmaster/autovacuum.c
@@ -2561,6 +2561,7 @@ deleted:
 	for (i = 0; i < NUM_WORKITEMS; i++)
 	{
 		AutoVacuumWorkItem *workitem = &AutoVacuumShmem->av_workItems[i];
+		AutoVacuumWorkItem my_workitem;
 
 		if (!workitem->avw_used)
 			continue;
@@ -2569,11 +2570,14 @@ deleted:
 		if (workitem->avw_database != MyDatabaseId)
 			continue;
 
+		my_workitem = *workitem;
+		workitem->avw_used = false;
+
 		/* claim this one, and release lock while performing it */
 		workitem->avw_active = true;
 		LWLockRelease(AutovacuumLock);
 
-		perform_work_item(workitem);
+		perform_work_item(&my_workitem);
 
 		/*
 		 * Check for config changes before acquiring lock for further jobs.