From 173cfc3762a97c300b618f863fd23433909cdb81 Mon Sep 17 00:00:00 2001
From: Yura Sokolov <y.sokolov@postgrespro.ru>
Date: Wed, 3 May 2023 18:48:46 +0300
Subject: [PATCH] PGPRO-8083: record timestamp in XLOG_BACKUP_END for
 recovery_target_time

It is useful for pg_probackup to recover on backup end.

Tags: pg_probackup
---
 src/backend/access/rmgrdesc/xlogdesc.c    | 15 +++++++--
 src/backend/access/transam/xlog.c         |  6 ++--
 src/backend/access/transam/xlogrecovery.c | 39 +++++++++++++++++++++++
 src/include/access/xlog_internal.h        |  7 ++++
 4 files changed, 62 insertions(+), 5 deletions(-)

diff --git a/src/backend/access/rmgrdesc/xlogdesc.c b/src/backend/access/rmgrdesc/xlogdesc.c
index 3fd7185f217..e1114168239 100644
--- a/src/backend/access/rmgrdesc/xlogdesc.c
+++ b/src/backend/access/rmgrdesc/xlogdesc.c
@@ -86,10 +86,19 @@ xlog_desc(StringInfo buf, XLogReaderState *record)
 	}
 	else if (info == XLOG_BACKUP_END)
 	{
-		XLogRecPtr	startpoint;
+		xl_backup_end	xlrec = {0, 0};
+		size_t			rec_len = XLogRecGetDataLen(record);
 
-		memcpy(&startpoint, rec, sizeof(XLogRecPtr));
-		appendStringInfo(buf, "%X/%X", LSN_FORMAT_ARGS(startpoint));
+		if (rec_len == sizeof(XLogRecPtr))
+			memcpy(&xlrec.startpoint, rec, sizeof(XLogRecPtr));
+		else if (rec_len >= sizeof(xl_backup_end))
+			memcpy(&xlrec, rec, sizeof(xl_backup_end));
+
+		appendStringInfo(buf, "%X/%X", LSN_FORMAT_ARGS(xlrec.startpoint));
+
+		if (rec_len >= sizeof(xl_backup_end))
+			appendStringInfo(buf, " at %s",
+							 timestamptz_to_str(xlrec.end_time));
 	}
 	else if (info == XLOG_PARAMETER_CHANGE)
 	{
diff --git a/src/backend/access/transam/xlog.c b/src/backend/access/transam/xlog.c
index 5ebb9783e2f..42cd06cd7d8 100644
--- a/src/backend/access/transam/xlog.c
+++ b/src/backend/access/transam/xlog.c
@@ -8680,14 +8680,16 @@ do_pg_backup_stop(BackupState *state, bool waitforarchive)
 	}
 	else
 	{
+		xl_backup_end	xlrec;
 		char	   *history_file;
 
 		/*
 		 * Write the backup-end xlog record
 		 */
+		xlrec.startpoint = state->startpoint;
+		xlrec.end_time = GetCurrentTimestamp();
 		XLogBeginInsert();
-		XLogRegisterData((char *) (&state->startpoint),
-						 sizeof(state->startpoint));
+		XLogRegisterData((char *) (&xlrec), sizeof(xlrec));
 		state->stoppoint = XLogInsert(RM_XLOG_ID, XLOG_BACKUP_END);
 
 		/*
diff --git a/src/backend/access/transam/xlogrecovery.c b/src/backend/access/transam/xlogrecovery.c
index 11747a6ff13..42d5b59ac25 100644
--- a/src/backend/access/transam/xlogrecovery.c
+++ b/src/backend/access/transam/xlogrecovery.c
@@ -2312,6 +2312,13 @@ getRecordTimestamp(XLogReaderState *record, TimestampTz *recordXtime)
 		*recordXtime = ((xl_restore_point *) XLogRecGetData(record))->rp_time;
 		return true;
 	}
+	if (rmid == RM_XLOG_ID && info == XLOG_BACKUP_END)
+	{
+		if (XLogRecGetDataLen(record) < sizeof(xl_backup_end))
+			return false;
+		*recordXtime = ((xl_backup_end *) XLogRecGetData(record))->end_time;
+		return true;
+	}
 	if (rmid == RM_XACT_ID && (xact_info == XLOG_XACT_COMMIT ||
 							   xact_info == XLOG_XACT_COMMIT_PREPARED))
 	{
@@ -2640,6 +2647,38 @@ recoveryStopsAfter(XLogReaderState *record)
 		}
 	}
 
+	if (recoveryTarget == RECOVERY_TARGET_TIME &&
+		rmid == RM_XLOG_ID && info == XLOG_BACKUP_END)
+	{
+		bool	stopsHere = false;
+
+		if (getRecordTimestamp(record, &recordXtime))
+		{
+			/*
+			 * Use same conditions as in recoveryStopsBefore for transaction
+			 * records to not override transactions time handling.
+			 */
+			if (recoveryTargetInclusive)
+				stopsHere = recordXtime > recoveryTargetTime;
+			else
+				stopsHere = recordXtime >= recoveryTargetTime;
+		}
+
+		if (stopsHere)
+		{
+			recoveryStopAfter = true;
+			recoveryStopXid = InvalidTransactionId;
+			recoveryStopLSN = InvalidXLogRecPtr;
+			recoveryStopTime = recordXtime;
+			recoveryStopName[0] = '\0';
+
+			ereport(LOG,
+					(errmsg("recovery stopping at backup end at time %s",
+							timestamptz_to_str(recoveryStopTime))));
+			return true;
+		}
+	}
+
 	/* Check if the target LSN has been reached */
 	if (recoveryTarget == RECOVERY_TARGET_LSN &&
 		recoveryTargetInclusive &&
diff --git a/src/include/access/xlog_internal.h b/src/include/access/xlog_internal.h
index e5fc66966bc..1bd0daf14a0 100644
--- a/src/include/access/xlog_internal.h
+++ b/src/include/access/xlog_internal.h
@@ -289,6 +289,13 @@ typedef struct xl_restore_point
 	char		rp_name[MAXFNAMELEN];
 } xl_restore_point;
 
+/* backup end record */
+typedef struct xl_backup_end
+{
+	XLogRecPtr	startpoint;
+	TimestampTz	end_time;
+} xl_backup_end;
+
 /* Overwrite of prior contrecord */
 typedef struct xl_overwrite_contrecord
 {
-- 
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