>From 9c4a7691595c1edfc12c5583cd007bb569f9db94 Mon Sep 17 00:00:00 2001
From: Andres Freund <andres@anarazel.de>
Date: Tue, 8 Dec 2015 13:56:18 +0100
Subject: [PATCH] Preliminary-unlogged-rel-recovery-fix

---
 src/backend/access/transam/xlogutils.c |  9 +++++++++
 src/backend/storage/buffer/bufmgr.c    | 21 +++++++++++++++++++++
 src/include/storage/bufmgr.h           |  1 +
 3 files changed, 31 insertions(+)

diff --git a/src/backend/access/transam/xlogutils.c b/src/backend/access/transam/xlogutils.c
index a5003c3..9073a85 100644
--- a/src/backend/access/transam/xlogutils.c
+++ b/src/backend/access/transam/xlogutils.c
@@ -368,6 +368,15 @@ XLogReadBufferForRedoExtended(XLogReaderState *record,
 
 		MarkBufferDirty(*buf);
 
+		/*
+		 * At the end of crash recovery the init forks of unlogged relations
+		 * are copied, without going through shared buffers. So we need to
+		 * force the on-disk state of init forks to always be in sync with the
+		 * state in shared buffers.
+		 */
+		if (forknum == INIT_FORKNUM)
+			FlushOneBuffer(*buf);
+
 		return BLK_RESTORED;
 	}
 	else
diff --git a/src/backend/storage/buffer/bufmgr.c b/src/backend/storage/buffer/bufmgr.c
index 63188a3..b32543b 100644
--- a/src/backend/storage/buffer/bufmgr.c
+++ b/src/backend/storage/buffer/bufmgr.c
@@ -2989,6 +2989,27 @@ FlushDatabaseBuffers(Oid dbid)
 }
 
 /*
+ * Flush a previously, shared or exclusively, locked and pinned buffer to the
+ * OS.
+ */
+void
+FlushOneBuffer(Buffer buffer)
+{
+	BufferDesc *bufHdr;
+
+	/* currently not needed, but no fundamental reason not to support */
+	Assert(!BufferIsLocal(buffer));
+
+	Assert(BufferIsPinned(buffer));
+
+	bufHdr = GetBufferDescriptor(buffer - 1);
+
+	LWLockHeldByMe(bufHdr->content_lock);
+
+	FlushBuffer(bufHdr, NULL);
+}
+
+/*
  * ReleaseBuffer -- release the pin on a buffer
  */
 void
diff --git a/src/include/storage/bufmgr.h b/src/include/storage/bufmgr.h
index 0f59201..09b2b11 100644
--- a/src/include/storage/bufmgr.h
+++ b/src/include/storage/bufmgr.h
@@ -176,6 +176,7 @@ extern void CheckPointBuffers(int flags);
 extern BlockNumber BufferGetBlockNumber(Buffer buffer);
 extern BlockNumber RelationGetNumberOfBlocksInFork(Relation relation,
 								ForkNumber forkNum);
+extern void FlushOneBuffer(Buffer buffer);
 extern void FlushRelationBuffers(Relation rel);
 extern void FlushDatabaseBuffers(Oid dbid);
 extern void DropRelFileNodeBuffers(RelFileNodeBackend rnode,
-- 
2.6.0.rc3