From 30845bf4a636516db8e17aa1c531d2d01cccbd1c Mon Sep 17 00:00:00 2001
From: Zhuravlev Uriy aka stalkerg <stalkerg@gmail.com>
Date: Thu, 10 Mar 2016 17:40:33 +0300
Subject: [PATCH] Check ptrack control file.

---
 backup.c    |  6 ++++++
 parsexlog.c |  2 --
 pg_arman.h  |  1 +
 util.c      | 15 +++++++++++++++
 4 files changed, 22 insertions(+), 2 deletions(-)

diff --git a/backup.c b/backup.c
index 7e09f08a..1f6addd0 100644
--- a/backup.c
+++ b/backup.c
@@ -230,6 +230,12 @@ do_backup_database(parray *backup_list, pgBackupOption bkupopt)
 
 	if (current.backup_mode == BACKUP_MODE_DIFF_PTRACK)
 	{
+		XLogRecPtr ptrack_lsn = get_last_ptrack_lsn();
+		if (ptrack_lsn < prev_backup->start_lsn || ptrack_lsn >= current.start_lsn)
+			elog(ERROR, "Wrong ptrack lsn:%lx prev:%lx current:%lx",
+				ptrack_lsn,
+				prev_backup->start_lsn,
+				current.start_lsn);
 		parray_qsort(backup_files_list, pgFileComparePathDesc);
 		make_pagemap_from_ptrack(backup_files_list);
 	}
diff --git a/parsexlog.c b/parsexlog.c
index 3487c351..21682766 100644
--- a/parsexlog.c
+++ b/parsexlog.c
@@ -107,11 +107,9 @@ SimpleXLogPageRead(XLogReaderState *xlogreader, XLogRecPtr targetPagePtr,
 {
 	XLogPageReadPrivate *private = (XLogPageReadPrivate *) xlogreader->private_data;
 	uint32		targetPageOff;
-	XLogRecPtr	targetSegEnd;
 	XLogSegNo	targetSegNo;
 
 	XLByteToSeg(targetPagePtr, targetSegNo);
-	XLogSegNoOffsetToRecPtr(targetSegNo + 1, 0, targetSegEnd);
 	targetPageOff = targetPagePtr % XLogSegSize;
 
 	/*
diff --git a/pg_arman.h b/pg_arman.h
index 82d16410..bb68fb18 100644
--- a/pg_arman.h
+++ b/pg_arman.h
@@ -298,6 +298,7 @@ extern void time2iso(char *buf, size_t len, time_t time);
 extern const char *status2str(BackupStatus status);
 extern void remove_trailing_space(char *buf, int comment_mark);
 extern void remove_not_digit(char *buf, size_t len, const char *str);
+extern XLogRecPtr get_last_ptrack_lsn(void);
 
 /* in status.c */
 extern bool is_pg_running(void);
diff --git a/util.c b/util.c
index 684ee668..b6a8f2a7 100644
--- a/util.c
+++ b/util.c
@@ -75,6 +75,21 @@ sanityChecks(void)
 			 "target master need to use either data checksums or \"wal_log_hints = on\".");
 }
 
+XLogRecPtr
+get_last_ptrack_lsn(void)
+{
+	char		*buffer;
+	size_t		size;
+	XLogRecPtr	lsn;
+
+	buffer = slurpFile(pgdata, "global/ptrack_control", &size, false);
+	if (buffer == NULL)
+		return 0;
+
+	lsn = *(XLogRecPtr *)buffer;
+	return lsn;
+}
+
 /*
  * Utility shared by backup and restore to fetch the current timeline
  * used by a node.