Force archive_status of .done for xlogs created by dearchival/replication.

This prevents spurious attempts to archive xlog files after promotion of
standby, a bug introduced by cascading replication patch in 9.2.

Fujii Masao, simplified and extended to cover streaming by Simon Riggs

Author: simonat2ndQuadrant

src/backend/access/transam/xlog.c

@@ -1335,6 +1335,59 @@ XLogArchiveNotifySeg(uint32 log, uint32 seg)
 	XLogArchiveNotify(xlog);
 }
 
+/*
+ * XLogArchiveForceDone
+ *
+ * Emit notification forcibly that an XLOG segment file has been successfully
+ * archived, by creating <XLOG>.done regardless of whether <XLOG>.ready
+ * exists or not.
+ */
+void
+XLogArchiveForceDone(const char *xlog)
+{
+	char		archiveReady[MAXPGPATH];
+	char		archiveDone[MAXPGPATH];
+	struct stat stat_buf;
+	FILE	   *fd;
+
+	/* Exit if already known done */
+	StatusFilePath(archiveDone, xlog, ".done");
+	if (stat(archiveDone, &stat_buf) == 0)
+		return;
+
+	/* If .ready exists, rename it to .done */
+	StatusFilePath(archiveReady, xlog, ".ready");
+	if (stat(archiveReady, &stat_buf) == 0)
+	{
+		if (rename(archiveReady, archiveDone) < 0)
+			ereport(WARNING,
+					(errcode_for_file_access(),
+					 errmsg("could not rename file \"%s\" to \"%s\": %m",
+							archiveReady, archiveDone)));
+
+		return;
+	}
+
+	/* insert an otherwise empty file called <XLOG>.done */
+	fd = AllocateFile(archiveDone, "w");
+	if (fd == NULL)
+	{
+		ereport(LOG,
+				(errcode_for_file_access(),
+				 errmsg("could not create archive status file \"%s\": %m",
+						archiveDone)));
+		return;
+	}
+	if (FreeFile(fd))
+	{
+		ereport(LOG,
+				(errcode_for_file_access(),
+				 errmsg("could not write archive status file \"%s\": %m",
+						archiveDone)));
+		return;
+	}
+}
+
 /*
  * XLogArchiveCheckDone
  *
@@ -2814,6 +2867,12 @@ XLogFileRead(uint32 log, uint32 seg, int emode, TimeLineID tli,
 		 */
 		strncpy(path, xlogfpath, MAXPGPATH);
 
+		/*
+		 * Create .done file forcibly to prevent the restored segment from
+		 * being archived again later.
+		 */
+		XLogArchiveForceDone(xlogfname);
+
 		/*
 		 * If the existing segment was replaced, since walsenders might have
 		 * it open, request them to reload a currently-open segment.

src/backend/replication/walreceiver.c

@@ -66,10 +66,12 @@ walrcv_disconnect_type walrcv_disconnect = NULL;
 #define NAPTIME_PER_CYCLE 100	/* max sleep time between cycles (100ms) */
 
 /*
- * These variables are used similarly to openLogFile/Id/Seg/Off,
- * but for walreceiver to write the XLOG.
+ * These variables are used similarly to openLogFile/SegNo/Off,
+ * but for walreceiver to write the XLOG. recvFileTLI is the TimeLineID
+ * corresponding the filename of recvFile.
  */
 static int	recvFile = -1;
+static TimeLineID	recvFileTLI = 0;
 static uint32 recvId = 0;
 static uint32 recvSeg = 0;
 static uint32 recvOff = 0;
@@ -492,6 +494,8 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 			 */
 			if (recvFile >= 0)
 			{
+				char		xlogfname[MAXFNAMELEN];
+
 				XLogWalRcvFlush(false);
 
 				/*
@@ -504,13 +508,21 @@ XLogWalRcvWrite(char *buf, Size nbytes, XLogRecPtr recptr)
 							(errcode_for_file_access(),
 						errmsg("could not close log file %u, segment %u: %m",
 							   recvId, recvSeg)));
+
+				/*
+				 * Create .done file forcibly to prevent the restored segment from
+				 * being archived again later.
+				 */
+				XLogFileName(xlogfname, recvFileTLI, recvId, recvSeg);
+				XLogArchiveForceDone(xlogfname);
 			}
 			recvFile = -1;
 
 			/* Create/use new log file */
 			XLByteToSeg(recptr, recvId, recvSeg);
 			use_existent = true;
 			recvFile = XLogFileInit(recvId, recvSeg, &use_existent, true);
+			recvFileTLI = ThisTimeLineID;
 			recvOff = 0;
 		}
 

src/include/access/xlog_internal.h

@@ -263,6 +263,11 @@ extern const RmgrData RmgrTable[];
 extern pg_time_t GetLastSegSwitchTime(void);
 extern XLogRecPtr RequestXLogSwitch(void);
 
+/*
+ * Exported to support xlog archive status setting from WALReceiver
+ */
+extern void XLogArchiveForceDone(const char *xlog);
+
 /*
  * These aren't in xlog.h because I'd rather not include fmgr.h there.
  */