From 0b7332ef5f65cc412dbf25e514185546cfef34d3 Mon Sep 17 00:00:00 2001
From: zhaosen <sen.zhao@enmotech.com>
Date: Fri, 10 May 2024 18:26:36 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8Dustore=E8=A7=86=E5=9B=BEgs=5F?=
 =?UTF-8?q?undo=5Fdump=5Fparsepage=5Fmv=E8=BF=90=E8=A1=8C=E9=80=BB?=
 =?UTF-8?q?=E8=BE=91=E4=B8=AD=E6=9C=AA=E8=80=83=E8=99=91xid=E7=9A=84?=
 =?UTF-8?q?=E7=BA=A6=E6=9D=9F=E6=9D=A1=E4=BB=B6=EF=BC=8C=E5=9C=A8=E9=81=8D?=
 =?UTF-8?q?=E5=8E=86TD=E9=93=BE=E6=97=B6=E4=BC=9A=E5=87=BA=E7=8E=B0?=
 =?UTF-8?q?=E6=AD=BB=E5=BE=AA=E7=8E=AF=E3=80=82?=
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---
 src/gausskernel/storage/page/pageparse.cpp | 21 ++++++++++++++++++++-
 1 file changed, 20 insertions(+), 1 deletion(-)

diff --git a/src/gausskernel/storage/page/pageparse.cpp b/src/gausskernel/storage/page/pageparse.cpp
index 17f6d1ad6..182d40fa5 100644
--- a/src/gausskernel/storage/page/pageparse.cpp
+++ b/src/gausskernel/storage/page/pageparse.cpp
@@ -1019,6 +1019,11 @@ static void DumpUndoRecordByUrpFromPage(void *page, ItemPointer ctid, UndoRecPtr
     int prevTdSlot = tdSlot;
     int currentTdSlot = tdSlot;
     UndoRecPtr currUrp = urp;
+    /*xid is the transaction ID we need for tuple's version when we traverse the TD chain,
+    for one version of tuple in undo_record, it's correct xid is stored in urec->OldXactId();
+    urec->Xid() represents the transaction ID that placed the undo_record into the undo segment. 
+    */
+    TransactionId xid = InvalidTransactionId;
 fetch_undo:
     VerifyMemoryContext();
     UndoRecord *urec = New(CurrentMemoryContext)UndoRecord();
@@ -1048,7 +1053,8 @@ fetch_undo:
         currentTdSlot = diskTuple->td_id;
 
         /* Find matched undo version, and output. */
-        if (ItemPointerGetBlockNumber(ctid) == urec->Blkno() && urec->Offset() == ctid->ip_posid) {
+        if (ItemPointerGetBlockNumber(ctid) == urec->Blkno() && urec->Offset() == ctid->ip_posid
+        && (!TransactionIdIsValid(xid) || TransactionIdEquals(xid, urec->Xid()))) {
             rc = snprintf_s(output + (int)strlen(output), MAXOUTPUTLEN, MAXOUTPUTLEN,
                 "\n\t\tUndoRecPtr(%lu): whdr = xid(%lu), cid(%u), reloid(%u), relfilenode(%u), utype(%u), uinfo(%u).\n",
                 urec->Urp(), urec->Xid(), urec->Cid(), urec->Reloid(), urec->Relfilenode(), urec->Utype(), urec->Uinfo());
@@ -1112,9 +1118,22 @@ fetch_undo:
                 "\n\t\tUndo diskTuple: td_id %u, reserved %u, flag %u, flag2 %u, t_hoff %u.\n",
                 diskTuple->td_id, diskTuple->reserved, diskTuple->flag, diskTuple->flag2, diskTuple->t_hoff);
             securec_check_ss(rc, "\0", "\0");
+        }else{
+            if (IS_VALID_UNDO_REC_PTR(urec->Blkprev())) {
+                currUrp = urec->Blkprev();
+                DELETE_EX(urec);
+                CHECK_FOR_INTERRUPTS();
+                goto fetch_undo;
+            }else{
+                goto fetch_end;
+            }
         }
+    }else{
+        goto fetch_end;
     }
 
+    xid = urec->OldXactId();
+
     if (prevTdSlot == currentTdSlot) {
         if (IS_VALID_UNDO_REC_PTR(urec->Blkprev())) {
             currUrp = urec->Blkprev();