4 files changed, 2 insertions, 870 deletions

diff --git a/src/backend/postmaster/Makefile b/src/backend/postmaster/Makefile
index ee8f8c1cd33..71c23211b2a 100644
--- a/src/backend/postmaster/Makefile
+++ b/src/backend/postmaster/Makefile
@@ -12,8 +12,7 @@ subdir = src/backend/postmaster
 top_builddir = ../../..
 include $(top_builddir)/src/Makefile.global
 
-OBJS = autovacuum.o bgworker.o bgwriter.o checkpointer.o checksumhelper.o \
-	fork_process.o pgarch.o pgstat.o postmaster.o startup.o syslogger.o \
-	walwriter.o
+OBJS = autovacuum.o bgworker.o bgwriter.o checkpointer.o fork_process.o \
+	pgarch.o pgstat.o postmaster.o startup.o syslogger.o walwriter.o
 
 include $(top_srcdir)/src/backend/common.mk
diff --git a/src/backend/postmaster/bgworker.c b/src/backend/postmaster/bgworker.c
index 19529d77ad6..f651bb49b15 100644
--- a/src/backend/postmaster/bgworker.c
+++ b/src/backend/postmaster/bgworker.c
@@ -20,7 +20,6 @@
 #include "pgstat.h"
 #include "port/atomics.h"
 #include "postmaster/bgworker_internals.h"
-#include "postmaster/checksumhelper.h"
 #include "postmaster/postmaster.h"
 #include "replication/logicallauncher.h"
 #include "replication/logicalworker.h"
@@ -130,12 +129,6 @@ static const struct
 	},
 	{
 		"ApplyWorkerMain", ApplyWorkerMain
-	},
-	{
-		"ChecksumHelperLauncherMain", ChecksumHelperLauncherMain
-	},
-	{
-		"ChecksumHelperWorkerMain", ChecksumHelperWorkerMain
 	}
 };
 
diff --git a/src/backend/postmaster/checksumhelper.c b/src/backend/postmaster/checksumhelper.c
deleted file mode 100644
index 288ab86336f..00000000000
--- a/src/backend/postmaster/checksumhelper.c
+++ /dev/null
@@ -1,855 +0,0 @@
-/*-------------------------------------------------------------------------
- *
- * checksumhelper.c
- *	  Background worker to walk the database and write checksums to pages
- *
- * When enabling data checksums on a database at initdb time, no extra process
- * is required as each page is checksummed, and verified, at accesses.  When
- * enabling checksums on an already running cluster, which was not initialized
- * with checksums, this helper worker will ensure that all pages are
- * checksummed before verification of the checksums is turned on.
- *
- * Portions Copyright (c) 1996-2018, PostgreSQL Global Development Group
- * Portions Copyright (c) 1994, Regents of the University of California
- *
- *
- * IDENTIFICATION
- *	  src/backend/postmaster/checksumhelper.c
- *
- *-------------------------------------------------------------------------
- */
-#include "postgres.h"
-
-#include "access/heapam.h"
-#include "access/htup_details.h"
-#include "access/xact.h"
-#include "catalog/pg_database.h"
-#include "commands/vacuum.h"
-#include "common/relpath.h"
-#include "miscadmin.h"
-#include "pgstat.h"
-#include "postmaster/bgworker.h"
-#include "postmaster/bgwriter.h"
-#include "postmaster/checksumhelper.h"
-#include "storage/bufmgr.h"
-#include "storage/checksum.h"
-#include "storage/lmgr.h"
-#include "storage/ipc.h"
-#include "storage/procarray.h"
-#include "storage/smgr.h"
-#include "tcop/tcopprot.h"
-#include "utils/lsyscache.h"
-#include "utils/ps_status.h"
-
-
-typedef enum
-{
-	SUCCESSFUL = 0,
-	ABORTED,
-	FAILED
-}			ChecksumHelperResult;
-
-typedef struct ChecksumHelperShmemStruct
-{
-	pg_atomic_flag launcher_started;
-	ChecksumHelperResult success;
-	bool		process_shared_catalogs;
-	bool		abort;
-	/* Parameter values set on start */
-	int			cost_delay;
-	int			cost_limit;
-}			ChecksumHelperShmemStruct;
-
-/* Shared memory segment for checksumhelper */
-static ChecksumHelperShmemStruct * ChecksumHelperShmem;
-
-/* Bookkeeping for work to do */
-typedef struct ChecksumHelperDatabase
-{
-	Oid			dboid;
-	char	   *dbname;
-}			ChecksumHelperDatabase;
-
-typedef struct ChecksumHelperRelation
-{
-	Oid			reloid;
-	char		relkind;
-}			ChecksumHelperRelation;
-
-/* Prototypes */
-static List *BuildDatabaseList(void);
-static List *BuildRelationList(bool include_shared);
-static List *BuildTempTableList(void);
-static ChecksumHelperResult ProcessDatabase(ChecksumHelperDatabase * db);
-static void launcher_cancel_handler(SIGNAL_ARGS);
-
-/*
- * Main entry point for checksumhelper launcher process.
- */
-bool
-StartChecksumHelperLauncher(int cost_delay, int cost_limit)
-{
-	BackgroundWorker bgw;
-	BackgroundWorkerHandle *bgw_handle;
-
-	if (ChecksumHelperShmem->abort)
-	{
-		ereport(ERROR,
-				(errmsg("could not start checksumhelper: has been cancelled")));
-	}
-
-	ChecksumHelperShmem->cost_delay = cost_delay;
-	ChecksumHelperShmem->cost_limit = cost_limit;
-
-	memset(&bgw, 0, sizeof(bgw));
-	bgw.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
-	bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
-	snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
-	snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ChecksumHelperLauncherMain");
-	snprintf(bgw.bgw_name, BGW_MAXLEN, "checksumhelper launcher");
-	snprintf(bgw.bgw_type, BGW_MAXLEN, "checksumhelper launcher");
-	bgw.bgw_restart_time = BGW_NEVER_RESTART;
-	bgw.bgw_notify_pid = MyProcPid;
-	bgw.bgw_main_arg = (Datum) 0;
-
-	if (!pg_atomic_test_set_flag(&ChecksumHelperShmem->launcher_started))
-	{
-		/* Failed to set means somebody else started */
-		ereport(ERROR,
-				(errmsg("could not start checksumhelper: already running")));
-	}
-
-	if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
-	{
-		pg_atomic_clear_flag(&ChecksumHelperShmem->launcher_started);
-		return false;
-	}
-
-	return true;
-}
-
-/*
- * ShutdownChecksumHelperIfRunning
- *		Request shutdown of the checksumhelper
- *
- * This does not turn off processing immediately, it signals the checksum
- * process to end when done with the current block.
- */
-void
-ShutdownChecksumHelperIfRunning(void)
-{
-	/* If the launcher isn't started, there is nothing to shut down */
-	if (pg_atomic_unlocked_test_flag(&ChecksumHelperShmem->launcher_started))
-		return;
-
-	/*
-	 * We don't need an atomic variable for aborting, setting it multiple
-	 * times will not change the handling.
-	 */
-	ChecksumHelperShmem->abort = true;
-}
-
-/*
- * ProcessSingleRelationFork
- *		Enable checksums in a single relation/fork.
- *
- * Returns true if successful, and false if *aborted*. On error, an actual
- * error is raised in the lower levels.
- */
-static bool
-ProcessSingleRelationFork(Relation reln, ForkNumber forkNum, BufferAccessStrategy strategy)
-{
-	BlockNumber numblocks = RelationGetNumberOfBlocksInFork(reln, forkNum);
-	BlockNumber b;
-	char		activity[NAMEDATALEN * 2 + 128];
-
-	for (b = 0; b < numblocks; b++)
-	{
-		Buffer		buf = ReadBufferExtended(reln, forkNum, b, RBM_NORMAL, strategy);
-
-		/*
-		 * Report to pgstat every 100 blocks (so as not to "spam")
-		 */
-		if ((b % 100) == 0)
-		{
-			snprintf(activity, sizeof(activity) - 1, "processing: %s.%s (%s block %d/%d)",
-					 get_namespace_name(RelationGetNamespace(reln)), RelationGetRelationName(reln),
-					 forkNames[forkNum], b, numblocks);
-			pgstat_report_activity(STATE_RUNNING, activity);
-		}
-
-		/* Need to get an exclusive lock before we can flag as dirty */
-		LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
-
-		/*
-		 * Mark the buffer as dirty and force a full page write.  We have to
-		 * re-write the page to WAL even if the checksum hasn't changed,
-		 * because if there is a replica it might have a slightly different
-		 * version of the page with an invalid checksum, caused by unlogged
-		 * changes (e.g. hintbits) on the master happening while checksums
-		 * were off. This can happen if there was a valid checksum on the page
-		 * at one point in the past, so only when checksums are first on, then
-		 * off, and then turned on again.
-		 */
-		START_CRIT_SECTION();
-		MarkBufferDirty(buf);
-		log_newpage_buffer(buf, false);
-		END_CRIT_SECTION();
-
-		UnlockReleaseBuffer(buf);
-
-		/*
-		 * This is the only place where we check if we are asked to abort, the
-		 * abortion will bubble up from here.
-		 */
-		if (ChecksumHelperShmem->abort)
-			return false;
-
-		vacuum_delay_point();
-	}
-
-	return true;
-}
-
-/*
- * ProcessSingleRelationByOid
- *		Process a single relation based on oid.
- *
- * Returns true if successful, and false if *aborted*. On error, an actual error
- * is raised in the lower levels.
- */
-static bool
-ProcessSingleRelationByOid(Oid relationId, BufferAccessStrategy strategy)
-{
-	Relation	rel;
-	ForkNumber	fnum;
-	bool		aborted = false;
-
-	StartTransactionCommand();
-
-	elog(DEBUG2, "Checksumhelper starting to process relation %d", relationId);
-	rel = try_relation_open(relationId, AccessShareLock);
-	if (rel == NULL)
-	{
-		/*
-		 * Relation no longer exist. We consider this a success, since there
-		 * are no pages in it that need checksums, and thus return true.
-		 */
-		elog(DEBUG1, "Checksumhelper skipping relation %d as it no longer exists", relationId);
-		CommitTransactionCommand();
-		pgstat_report_activity(STATE_IDLE, NULL);
-		return true;
-	}
-	RelationOpenSmgr(rel);
-
-	for (fnum = 0; fnum <= MAX_FORKNUM; fnum++)
-	{
-		if (smgrexists(rel->rd_smgr, fnum))
-		{
-			if (!ProcessSingleRelationFork(rel, fnum, strategy))
-			{
-				aborted = true;
-				break;
-			}
-		}
-	}
-	relation_close(rel, AccessShareLock);
-	elog(DEBUG2, "Checksumhelper done with relation %d: %s",
-		 relationId, (aborted ? "aborted" : "finished"));
-
-	CommitTransactionCommand();
-
-	pgstat_report_activity(STATE_IDLE, NULL);
-
-	return !aborted;
-}
-
-/*
- * ProcessDatabase
- *		Enable checksums in a single database.
- *
- * We do this by launching a dynamic background worker into this database, and
- * waiting for it to finish.  We have to do this in a separate worker, since
- * each process can only be connected to one database during its lifetime.
- */
-static ChecksumHelperResult
-ProcessDatabase(ChecksumHelperDatabase * db)
-{
-	BackgroundWorker bgw;
-	BackgroundWorkerHandle *bgw_handle;
-	BgwHandleStatus status;
-	pid_t		pid;
-	char		activity[NAMEDATALEN + 64];
-
-	ChecksumHelperShmem->success = FAILED;
-
-	memset(&bgw, 0, sizeof(bgw));
-	bgw.bgw_flags = BGWORKER_SHMEM_ACCESS | BGWORKER_BACKEND_DATABASE_CONNECTION;
-	bgw.bgw_start_time = BgWorkerStart_RecoveryFinished;
-	snprintf(bgw.bgw_library_name, BGW_MAXLEN, "postgres");
-	snprintf(bgw.bgw_function_name, BGW_MAXLEN, "ChecksumHelperWorkerMain");
-	snprintf(bgw.bgw_name, BGW_MAXLEN, "checksumhelper worker");
-	snprintf(bgw.bgw_type, BGW_MAXLEN, "checksumhelper worker");
-	bgw.bgw_restart_time = BGW_NEVER_RESTART;
-	bgw.bgw_notify_pid = MyProcPid;
-	bgw.bgw_main_arg = ObjectIdGetDatum(db->dboid);
-
-	if (!RegisterDynamicBackgroundWorker(&bgw, &bgw_handle))
-	{
-		ereport(LOG,
-				(errmsg("failed to start worker for checksumhelper in \"%s\"",
-						db->dbname)));
-		return FAILED;
-	}
-
-	status = WaitForBackgroundWorkerStartup(bgw_handle, &pid);
-	if (status != BGWH_STARTED)
-	{
-		ereport(LOG,
-				(errmsg("failed to wait for worker startup for checksumhelper in \"%s\"",
-						db->dbname)));
-		return FAILED;
-	}
-
-	ereport(DEBUG1,
-			(errmsg("started background worker for checksums in \"%s\"",
-					db->dbname)));
-
-	snprintf(activity, sizeof(activity) - 1,
-			 "Waiting for worker in database %s (pid %d)", db->dbname, pid);
-	pgstat_report_activity(STATE_RUNNING, activity);
-
-
-	status = WaitForBackgroundWorkerShutdown(bgw_handle);
-	if (status != BGWH_STOPPED)
-	{
-		ereport(LOG,
-				(errmsg("failed to wait for worker shutdown for checksumhelper in \"%s\"",
-						db->dbname)));
-		return FAILED;
-	}
-
-	if (ChecksumHelperShmem->success == ABORTED)
-		ereport(LOG,
-				(errmsg("checksumhelper was aborted during processing in \"%s\"",
-						db->dbname)));
-
-	ereport(DEBUG1,
-			(errmsg("background worker for checksums in \"%s\" completed",
-					db->dbname)));
-
-	pgstat_report_activity(STATE_IDLE, NULL);
-
-	return ChecksumHelperShmem->success;
-}
-
-static void
-launcher_exit(int code, Datum arg)
-{
-	ChecksumHelperShmem->abort = false;
-	pg_atomic_clear_flag(&ChecksumHelperShmem->launcher_started);
-}
-
-static void
-launcher_cancel_handler(SIGNAL_ARGS)
-{
-	ChecksumHelperShmem->abort = true;
-}
-
-static void
-WaitForAllTransactionsToFinish(void)
-{
-	TransactionId waitforxid;
-
-	LWLockAcquire(XidGenLock, LW_SHARED);
-	waitforxid = ShmemVariableCache->nextXid;
-	LWLockRelease(XidGenLock);
-
-	while (true)
-	{
-		TransactionId oldestxid = GetOldestActiveTransactionId();
-
-		elog(DEBUG1, "Checking old transactions");
-		if (TransactionIdPrecedes(oldestxid, waitforxid))
-		{
-			char		activity[64];
-
-			/* Oldest running xid is older than us, so wait */
-			snprintf(activity, sizeof(activity), "Waiting for current transactions to finish (waiting for %d)", waitforxid);
-			pgstat_report_activity(STATE_RUNNING, activity);
-
-			/* Retry every 5 seconds */
-			ResetLatch(MyLatch);
-			(void) WaitLatch(MyLatch,
-							 WL_LATCH_SET | WL_TIMEOUT,
-							 5000,
-							 WAIT_EVENT_PG_SLEEP);
-		}
-		else
-		{
-			pgstat_report_activity(STATE_IDLE, NULL);
-			return;
-		}
-	}
-}
-
-void
-ChecksumHelperLauncherMain(Datum arg)
-{
-	List	   *DatabaseList;
-	List	   *remaining = NIL;
-	ListCell   *lc,
-			   *lc2;
-	List	   *CurrentDatabases = NIL;
-	bool		found_failed = false;
-
-	on_shmem_exit(launcher_exit, 0);
-
-	ereport(DEBUG1,
-			(errmsg("checksumhelper launcher started")));
-
-	pqsignal(SIGTERM, die);
-	pqsignal(SIGINT, launcher_cancel_handler);
-
-	BackgroundWorkerUnblockSignals();
-
-	init_ps_display(pgstat_get_backend_desc(B_CHECKSUMHELPER_LAUNCHER), "", "", "");
-
-	/*
-	 * Initialize a connection to shared catalogs only.
-	 */
-	BackgroundWorkerInitializeConnection(NULL, NULL, 0);
-
-	/*
-	 * Set up so first run processes shared catalogs, but not once in every
-	 * db.
-	 */
-	ChecksumHelperShmem->process_shared_catalogs = true;
-
-	/*
-	 * Wait for all existing transactions to finish. This will make sure that
-	 * we can see all tables all databases, so we don't miss any. Anything
-	 * created after this point is known to have checksums on all pages
-	 * already, so we don't have to care about those.
-	 */
-	WaitForAllTransactionsToFinish();
-
-	/*
-	 * Create a database list.  We don't need to concern ourselves with
-	 * rebuilding this list during runtime since any database created after
-	 * this process started will be running with checksums turned on from the
-	 * start.
-	 */
-	DatabaseList = BuildDatabaseList();
-
-	/*
-	 * If there are no databases at all to checksum, we can exit immediately
-	 * as there is no work to do.
-	 */
-	if (DatabaseList == NIL || list_length(DatabaseList) == 0)
-		return;
-
-	foreach(lc, DatabaseList)
-	{
-		ChecksumHelperDatabase *db = (ChecksumHelperDatabase *) lfirst(lc);
-		ChecksumHelperResult processing;
-
-		processing = ProcessDatabase(db);
-
-		if (processing == SUCCESSFUL)
-		{
-			pfree(db->dbname);
-			pfree(db);
-
-			if (ChecksumHelperShmem->process_shared_catalogs)
-
-				/*
-				 * Now that one database has completed shared catalogs, we
-				 * don't have to process them again.
-				 */
-				ChecksumHelperShmem->process_shared_catalogs = false;
-		}
-		else if (processing == FAILED)
-		{
-			/*
-			 * Put failed databases on the remaining list.
-			 */
-			remaining = lappend(remaining, db);
-		}
-		else
-			/* aborted */
-			return;
-	}
-	list_free(DatabaseList);
-
-	/*
-	 * remaining now has all databases not yet processed. This can be because
-	 * they failed for some reason, or because the database was dropped
-	 * between us getting the database list and trying to process it. Get a
-	 * fresh list of databases to detect the second case where the database
-	 * was dropped before we had started processing it. If a database still
-	 * exists, but enabling checksums failed then we fail the entire
-	 * checksumming process and exit with an error.
-	 */
-	CurrentDatabases = BuildDatabaseList();
-
-	foreach(lc, remaining)
-	{
-		ChecksumHelperDatabase *db = (ChecksumHelperDatabase *) lfirst(lc);
-		bool		found = false;
-
-		foreach(lc2, CurrentDatabases)
-		{
-			ChecksumHelperDatabase *db2 = (ChecksumHelperDatabase *) lfirst(lc2);
-
-			if (db->dboid == db2->dboid)
-			{
-				found = true;
-				ereport(WARNING,
-						(errmsg("failed to enable checksums in \"%s\"",
-								db->dbname)));
-				break;
-			}
-		}
-
-		if (found)
-			found_failed = true;
-		else
-		{
-			ereport(LOG,
-					(errmsg("database \"%s\" has been dropped, skipping",
-							db->dbname)));
-		}
-
-		pfree(db->dbname);
-		pfree(db);
-	}
-	list_free(remaining);
-
-	/* Free the extra list of databases */
-	foreach(lc, CurrentDatabases)
-	{
-		ChecksumHelperDatabase *db = (ChecksumHelperDatabase *) lfirst(lc);
-
-		pfree(db->dbname);
-		pfree(db);
-	}
-	list_free(CurrentDatabases);
-
-	if (found_failed)
-	{
-		/* Disable checksums on cluster, because we failed */
-		SetDataChecksumsOff();
-		ereport(ERROR,
-				(errmsg("checksumhelper failed to enable checksums in all databases, aborting")));
-	}
-
-	/*
-	 * Force a checkpoint to get everything out to disk.
-	 */
-	RequestCheckpoint(CHECKPOINT_FORCE | CHECKPOINT_WAIT | CHECKPOINT_IMMEDIATE);
-
-	/*
-	 * Everything has been processed, so flag checksums enabled.
-	 */
-	SetDataChecksumsOn();
-
-	ereport(LOG,
-			(errmsg("checksums enabled, checksumhelper launcher shutting down")));
-}
-
-/*
- * ChecksumHelperShmemSize
- *		Compute required space for checksumhelper-related shared memory
- */
-Size
-ChecksumHelperShmemSize(void)
-{
-	Size		size;
-
-	size = sizeof(ChecksumHelperShmemStruct);
-	size = MAXALIGN(size);
-
-	return size;
-}
-
-/*
- * ChecksumHelperShmemInit
- *		Allocate and initialize checksumhelper-related shared memory
- */
-void
-ChecksumHelperShmemInit(void)
-{
-	bool		found;
-
-	ChecksumHelperShmem = (ChecksumHelperShmemStruct *)
-		ShmemInitStruct("ChecksumHelper Data",
-						ChecksumHelperShmemSize(),
-						&found);
-
-	if (!found)
-	{
-		MemSet(ChecksumHelperShmem, 0, ChecksumHelperShmemSize());
-		pg_atomic_init_flag(&ChecksumHelperShmem->launcher_started);
-	}
-}
-
-/*
- * BuildDatabaseList
- *		Compile a list of all currently available databases in the cluster
- *
- * This creates the list of databases for the checksumhelper workers to add
- * checksums to.
- */
-static List *
-BuildDatabaseList(void)
-{
-	List	   *DatabaseList = NIL;
-	Relation	rel;
-	HeapScanDesc scan;
-	HeapTuple	tup;
-	MemoryContext ctx = CurrentMemoryContext;
-	MemoryContext oldctx;
-
-	StartTransactionCommand();
-
-	rel = heap_open(DatabaseRelationId, AccessShareLock);
-	scan = heap_beginscan_catalog(rel, 0, NULL);
-
-	while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
-	{
-		Form_pg_database pgdb = (Form_pg_database) GETSTRUCT(tup);
-		ChecksumHelperDatabase *db;
-
-		oldctx = MemoryContextSwitchTo(ctx);
-
-		db = (ChecksumHelperDatabase *) palloc(sizeof(ChecksumHelperDatabase));
-
-		db->dboid = HeapTupleGetOid(tup);
-		db->dbname = pstrdup(NameStr(pgdb->datname));
-
-		DatabaseList = lappend(DatabaseList, db);
-
-		MemoryContextSwitchTo(oldctx);
-	}
-
-	heap_endscan(scan);
-	heap_close(rel, AccessShareLock);
-
-	CommitTransactionCommand();
-
-	return DatabaseList;
-}
-
-/*
- * BuildRelationList
- *		Compile a list of all relations in the database
- *
- * If shared is true, both shared relations and local ones are returned, else
- * all non-shared relations are returned.
- * Temp tables are not included.
- */
-static List *
-BuildRelationList(bool include_shared)
-{
-	List	   *RelationList = NIL;
-	Relation	rel;
-	HeapScanDesc scan;
-	HeapTuple	tup;
-	MemoryContext ctx = CurrentMemoryContext;
-	MemoryContext oldctx;
-
-	StartTransactionCommand();
-
-	rel = heap_open(RelationRelationId, AccessShareLock);
-	scan = heap_beginscan_catalog(rel, 0, NULL);
-
-	while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
-	{
-		Form_pg_class pgc = (Form_pg_class) GETSTRUCT(tup);
-		ChecksumHelperRelation *relentry;
-
-		if (pgc->relpersistence == 't')
-			continue;
-
-		if (pgc->relisshared && !include_shared)
-			continue;
-
-		/*
-		 * Foreign tables have by definition no local storage that can be
-		 * checksummed, so skip.
-		 */
-		if (pgc->relkind == RELKIND_FOREIGN_TABLE)
-			continue;
-
-		oldctx = MemoryContextSwitchTo(ctx);
-		relentry = (ChecksumHelperRelation *) palloc(sizeof(ChecksumHelperRelation));
-
-		relentry->reloid = HeapTupleGetOid(tup);
-		relentry->relkind = pgc->relkind;
-
-		RelationList = lappend(RelationList, relentry);
-
-		MemoryContextSwitchTo(oldctx);
-	}
-
-	heap_endscan(scan);
-	heap_close(rel, AccessShareLock);
-
-	CommitTransactionCommand();
-
-	return RelationList;
-}
-
-/*
- * BuildTempTableList
- *		Compile a list of all temporary tables in database
- *
- * Returns a List of oids.
- */
-static List *
-BuildTempTableList(void)
-{
-	List	   *RelationList = NIL;
-	Relation	rel;
-	HeapScanDesc scan;
-	HeapTuple	tup;
-	MemoryContext ctx = CurrentMemoryContext;
-	MemoryContext oldctx;
-
-	StartTransactionCommand();
-
-	rel = heap_open(RelationRelationId, AccessShareLock);
-	scan = heap_beginscan_catalog(rel, 0, NULL);
-
-	while (HeapTupleIsValid(tup = heap_getnext(scan, ForwardScanDirection)))
-	{
-		Form_pg_class pgc = (Form_pg_class) GETSTRUCT(tup);
-
-		if (pgc->relpersistence != 't')
-			continue;
-
-		oldctx = MemoryContextSwitchTo(ctx);
-		RelationList = lappend_oid(RelationList, HeapTupleGetOid(tup));
-		MemoryContextSwitchTo(oldctx);
-	}
-
-	heap_endscan(scan);
-	heap_close(rel, AccessShareLock);
-
-	CommitTransactionCommand();
-
-	return RelationList;
-}
-
-/*
- * Main function for enabling checksums in a single database
- */
-void
-ChecksumHelperWorkerMain(Datum arg)
-{
-	Oid			dboid = DatumGetObjectId(arg);
-	List	   *RelationList = NIL;
-	List	   *InitialTempTableList = NIL;
-	ListCell   *lc;
-	BufferAccessStrategy strategy;
-	bool		aborted = false;
-
-	pqsignal(SIGTERM, die);
-
-	BackgroundWorkerUnblockSignals();
-
-	init_ps_display(pgstat_get_backend_desc(B_CHECKSUMHELPER_WORKER), "", "", "");
-
-	ereport(DEBUG1,
-			(errmsg("checksum worker starting for database oid %d", dboid)));
-
-	BackgroundWorkerInitializeConnectionByOid(dboid, InvalidOid, BGWORKER_BYPASS_ALLOWCONN);
-
-	/*
-	 * Get a list of all temp tables present as we start in this database. We
-	 * need to wait until they are all gone until we are done, since we cannot
-	 * access those files and modify them.
-	 */
-	InitialTempTableList = BuildTempTableList();
-
-	/*
-	 * Enable vacuum cost delay, if any.
-	 */
-	VacuumCostDelay = ChecksumHelperShmem->cost_delay;
-	VacuumCostLimit = ChecksumHelperShmem->cost_limit;
-	VacuumCostActive = (VacuumCostDelay > 0);
-	VacuumCostBalance = 0;
-	VacuumPageHit = 0;
-	VacuumPageMiss = 0;
-	VacuumPageDirty = 0;
-
-	/*
-	 * Create and set the vacuum strategy as our buffer strategy.
-	 */
-	strategy = GetAccessStrategy(BAS_VACUUM);
-
-	RelationList = BuildRelationList(ChecksumHelperShmem->process_shared_catalogs);
-	foreach(lc, RelationList)
-	{
-		ChecksumHelperRelation *rel = (ChecksumHelperRelation *) lfirst(lc);
-
-		if (!ProcessSingleRelationByOid(rel->reloid, strategy))
-		{
-			aborted = true;
-			break;
-		}
-	}
-	list_free_deep(RelationList);
-
-	if (aborted)
-	{
-		ChecksumHelperShmem->success = ABORTED;
-		ereport(DEBUG1,
-				(errmsg("checksum worker aborted in database oid %d", dboid)));
-		return;
-	}
-
-	/*
-	 * Wait for all temp tables that existed when we started to go away. This
-	 * is necessary since we cannot "reach" them to enable checksums. Any temp
-	 * tables created after we started will already have checksums in them
-	 * (due to the inprogress state), so those are safe.
-	 */
-	while (true)
-	{
-		List	   *CurrentTempTables;
-		ListCell   *lc;
-		int			numleft;
-		char		activity[64];
-
-		CurrentTempTables = BuildTempTableList();
-		numleft = 0;
-		foreach(lc, InitialTempTableList)
-		{
-			if (list_member_oid(CurrentTempTables, lfirst_oid(lc)))
-				numleft++;
-		}
-		list_free(CurrentTempTables);
-
-		if (numleft == 0)
-			break;
-
-		/* At least one temp table left to wait for */
-		snprintf(activity, sizeof(activity), "Waiting for %d temp tables to be removed", numleft);
-		pgstat_report_activity(STATE_RUNNING, activity);
-
-		/* Retry every 5 seconds */
-		ResetLatch(MyLatch);
-		(void) WaitLatch(MyLatch,
-						 WL_LATCH_SET | WL_TIMEOUT,
-						 5000,
-						 WAIT_EVENT_PG_SLEEP);
-	}
-
-	list_free(InitialTempTableList);
-
-	ChecksumHelperShmem->success = SUCCESSFUL;
-	ereport(DEBUG1,
-			(errmsg("checksum worker completed in database oid %d", dboid)));
-}
diff --git a/src/backend/postmaster/pgstat.c b/src/backend/postmaster/pgstat.c
index 83328a27662..96ba2163878 100644
--- a/src/backend/postmaster/pgstat.c
+++ b/src/backend/postmaster/pgstat.c
@@ -4125,11 +4125,6 @@ pgstat_get_backend_desc(BackendType backendType)
 		case B_WAL_WRITER:
 			backendDesc = "walwriter";
 			break;
-		case B_CHECKSUMHELPER_LAUNCHER:
-			backendDesc = "checksumhelper launcher";
-			break;
-		case B_CHECKSUMHELPER_WORKER:
-			backendDesc = "checksumhelper worker";
 	}
 
 	return backendDesc;