From: Vadim B. Mikheev <vadim4o@yahoo.com>
Date: Wed, 4 Apr 2001 15:43:25 +0000 (+0000)
Subject: Have to lock buffer while changing page' LSN.
X-Git-Url: http://waps.l3s.uni-hannover.de/gitweb/?a=commitdiff_plain;h=84b96085ba580a5442d144735c627dc3a9f266e7;p=users%2Fbernd%2Fpostgres.git

Have to lock buffer while changing page' LSN.
Thanks to Tom.
---

diff --git a/src/backend/commands/sequence.c b/src/backend/commands/sequence.c
index 6c7c7a7a3b..a89ba2e5fd 100644
--- a/src/backend/commands/sequence.c
+++ b/src/backend/commands/sequence.c
@@ -181,13 +181,13 @@ DefineSequence(CreateSeqStmt *seq)
 	/* Now - form & insert sequence tuple */
 	tuple = heap_formtuple(tupDesc, value, null);
 	heap_insert(rel, tuple);
-	ReleaseBuffer(buf);
 
 	/*
 	 * After crash REDO of heap_insert above would re-init page and
 	 * our magic number would be lost. We have to log sequence creation.
 	 * This means two log records instead of one -:(
 	 */
+	LockBuffer(buf, BUFFER_LOCK_EXCLUSIVE);
 	START_CRIT_SECTION();
 	{
 		xl_seq_rec			xlrec;
@@ -217,6 +217,8 @@ DefineSequence(CreateSeqStmt *seq)
 	}
 	END_CRIT_SECTION();
 
+	LockBuffer(buf, BUFFER_LOCK_UNLOCK);
+	ReleaseBuffer(buf);
 	heap_close(rel, AccessExclusiveLock);
 }