From 490edec3ee5f58d531d574cd2587f7d2a1b2cab5 Mon Sep 17 00:00:00 2001
From: "arcoalien@qq.com" <arcoalien@qq.com>
Date: Wed, 22 Mar 2023 20:08:55 +0800
Subject: [PATCH] =?UTF-8?q?=E4=BF=AE=E5=A4=8D=E5=9B=9E=E6=94=BE=E8=BF=87?=
 =?UTF-8?q?=E7=A8=8B=E4=B8=AD=E9=81=87=E5=88=B0read=20mode=E6=98=AFzero=20?=
 =?UTF-8?q?and=20lock=E5=AF=BC=E8=87=B4=E7=9A=84=E5=8F=8D=E5=A4=8D?=
 =?UTF-8?q?=E4=B8=8A=E9=94=81?=
MIME-Version: 1.0
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 8bit

---
 .../storage/access/transam/xlogutils.cpp      | 28 +++++++++++--------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/src/gausskernel/storage/access/transam/xlogutils.cpp b/src/gausskernel/storage/access/transam/xlogutils.cpp
index 732931df8..6692dca39 100644
--- a/src/gausskernel/storage/access/transam/xlogutils.cpp
+++ b/src/gausskernel/storage/access/transam/xlogutils.cpp
@@ -1146,13 +1146,15 @@ Buffer XLogReadBufferExtendedForHeapDisk(const RelFileNode &rnode, ForkNumber fo
          * there should be no other backends that could modify the buffer at
          * the same time.
          */
-        if (ENABLE_DMS) {
+        bool buffer_is_locked = false;
+        if (ENABLE_DMS && (GetDmsBufCtrl(buffer - 1)->lock_mode == DMS_LOCK_NULL)) {
+            buffer_is_locked = true;
             LockBuffer(buffer, BUFFER_LOCK_SHARE);
         }
 
         if (PageIsNew(page)) {
             Assert(!PageIsLogical(page));
-            if (ENABLE_DMS) {
+            if (ENABLE_DMS && buffer_is_locked) {
                 LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
             }
             ReleaseBuffer(buffer);
@@ -1166,7 +1168,7 @@ Buffer XLogReadBufferExtendedForHeapDisk(const RelFileNode &rnode, ForkNumber fo
             return InvalidBuffer;
         }
 
-        if (ENABLE_DMS) {
+        if (ENABLE_DMS && buffer_is_locked) {
             LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
         }
     }
@@ -1217,14 +1219,16 @@ Buffer XLogReadBufferExtendedForSegpage(const RelFileNode &rnode, ForkNumber for
 
     if (BufferIsValid(buffer)) {
         Page page = BufferGetPage(buffer);
-        if (ENABLE_DMS) {
-            LockBuffer(buffer, BUFFER_LOCK_SHARE);
-        }
-
         if (mode == RBM_NORMAL) {
+            bool buffer_is_locked = false;
+            if (ENABLE_DMS && (GetDmsBufCtrl(buffer - 1)->lock_mode == DMS_LOCK_NULL)) {
+                buffer_is_locked = true;
+                LockBuffer(buffer, BUFFER_LOCK_SHARE);
+            }
+
             if (PageIsNew(page)) {
                 SegmentCheck(XLogRecPtrIsInvalid(PageGetLSN(page)));
-                if (ENABLE_DMS) {
+                if (ENABLE_DMS && buffer_is_locked) {
                     LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
                 }
                 SegReleaseBuffer(buffer);
@@ -1238,14 +1242,14 @@ Buffer XLogReadBufferExtendedForSegpage(const RelFileNode &rnode, ForkNumber for
                 log_invalid_page(rnode, forknum, blkno, NOT_INITIALIZED, NULL);
                 return InvalidBuffer;
             }
+
+            if (ENABLE_DMS && buffer_is_locked) {
+                LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
+            }
         }
         if (t_thrd.xlog_cxt.startup_processing && t_thrd.xlog_cxt.server_mode == STANDBY_MODE && PageIsLogical(page)) {
             PageClearLogical(page);
         }
-
-        if (ENABLE_DMS) {
-            LockBuffer(buffer, BUFFER_LOCK_UNLOCK);
-        }
     } else {
         ereport(ERROR, (errcode_for_file_access(),
                             errmsg("block is invalid %u/%u/%u %d %u", rnode.spcNode, rnode.dbNode, rnode.relNode,