From: Robert Haas <rhaas@postgresql.org>
Date: Thu, 9 Dec 2021 23:15:56 +0000 (-0500)
Subject: when vacuuming, handle uninitialized index pages without barfing
X-Git-Url: http://git.postgresql.org/gitweb/?a=commitdiff_plain;h=ddd50d0488db184290700c644e546b217cdcc8c8;p=users%2Frhaas%2Fpostgres.git

when vacuuming, handle uninitialized index pages without barfing
---

diff --git a/src/backend/access/conveyor/conveyor.c b/src/backend/access/conveyor/conveyor.c
index cb6adab6ce..431a01c9f8 100644
--- a/src/backend/access/conveyor/conveyor.c
+++ b/src/backend/access/conveyor/conveyor.c
@@ -1267,6 +1267,23 @@ ConveyorBeltClearIndexSegmentEntries(ConveyorBelt *cb, Buffer metabuffer,
 		indexbuffer = ConveyorBeltRead(cb, indexblock, BUFFER_LOCK_EXCLUSIVE);
 		indexpage = BufferGetPage(indexbuffer);
 
+		/*
+		 * If an index segment page is not initialized, treat it the same
+		 * way as if it is initialized but contains no entries.
+		 */
+		if (ConveyorBeltPageIsUnused(indexpage))
+		{
+			if (segoff == 0)
+				elog(ERROR,
+					 "conveyor belt index page at segno %u offset 0 should be initialied",
+					 index_segment);
+			if (*next_index_segment != CB_INVALID_SEGMENT)
+				elog(ERROR,
+					 "non-final index segment page at segno %u offset %u should be initialized",
+					 index_segment, segoff);
+			return true;
+		}
+
 		/*
 		 * If this is the very first time we've locked an index page in this
 		 * segment, it should be the first page, and it will tell us where to