0001-Update-minimum-recovery-point-on-file-deletion-durin.patch

From a7e1fcec841223121c04883b9ce1e32b70574c62 Mon Sep 17 00:00:00 2001
From: "suyu.cmj" <mengjuan.cmj@alibaba-inc.com>
Date: Tue, 27 Jul 2021 16:23:05 +0000
Subject: [PATCH] Update minimum recovery point on file deletion during redo
 abort xlog record.

    If a file is deleted during redo abort xlog record, we must update minRecoveryPoint.
    Once a file is deleted, there's no going back; it would not be safe to stop recovery
    at a point earlier than that anymore.
---
 src/backend/access/transam/xact.c | 25 +++++++++++++++++++++++--
 1 file changed, 23 insertions(+), 2 deletions(-)

diff --git a/src/backend/access/transam/xact.c b/src/backend/access/transam/xact.c
index 4414459..78394d6 100644
--- a/src/backend/access/transam/xact.c
+++ b/src/backend/access/transam/xact.c
@@ -5982,8 +5982,29 @@ xact_redo_abort(xl_xact_parsed_abort *parsed, TransactionId xid,
 						   false /* backward */ , false /* WAL */ );
 	}
 
-	/* Make sure files supposed to be dropped are dropped */
-	DropRelationFiles(parsed->xnodes, parsed->nrels, true);
+	if (parsed->nrels > 0)
+	{
+		/*
+		 * First update minimum recovery point to cover this WAL record. Once
+		 * a relation is deleted, there's no going back. The buffer manager
+		 * enforces the WAL-first rule for normal updates to relation files,
+		 * so that the minimum recovery point is always updated before the
+		 * corresponding change in the data file is flushed to disk. We have
+		 * to do the same here. 
+		 *
+		 * Doing this before deleting the files means that if a deletion fails
+		 * for some reason, you cannot start up the system even after restart,
+		 * until you fix the underlying situation so that the deletion will
+		 * succeed. Alternatively, we could update the minimum recovery point
+		 * after deletion, but that would leave a small window where the
+		 * WAL-first rule would be violated. 
+		 */
+		XLogFlush(lsn);
+
+		/* Make sure files supposed to be dropped are dropped */
+		DropRelationFiles(parsed->xnodes, parsed->nrels, true);
+	}
+
 }
 
 void
-- 
1.8.3.1