3 files changed, 101 insertions, 42 deletions

diff --git a/src/bin/pg_rewind/pg_rewind.c b/src/bin/pg_rewind/pg_rewind.c
index aa753bb315f..7f1d6bf48af 100644
--- a/src/bin/pg_rewind/pg_rewind.c
+++ b/src/bin/pg_rewind/pg_rewind.c
@@ -24,6 +24,7 @@
 #include "access/xlog_internal.h"
 #include "catalog/catversion.h"
 #include "catalog/pg_control.h"
+#include "common/controldata_utils.h"
 #include "common/file_perm.h"
 #include "common/file_utils.h"
 #include "common/restricted_token.h"
@@ -37,7 +38,6 @@ static void createBackupLabel(XLogRecPtr startpoint, TimeLineID starttli,
 
 static void digestControlFile(ControlFileData *ControlFile, char *source,
 				  size_t size);
-static void updateControlFile(ControlFileData *ControlFile);
 static void syncTargetDirectory(void);
 static void sanityChecks(void);
 static void findCommonAncestorTimeline(XLogRecPtr *recptr, int *tliIndex);
@@ -377,7 +377,7 @@ main(int argc, char **argv)
 	ControlFile_new.minRecoveryPoint = endrec;
 	ControlFile_new.minRecoveryPointTLI = endtli;
 	ControlFile_new.state = DB_IN_ARCHIVE_RECOVERY;
-	updateControlFile(&ControlFile_new);
+	update_controlfile(datadir_target, progname, &ControlFile_new);
 
 	pg_log(PG_PROGRESS, "syncing target data directory\n");
 	syncTargetDirectory();
@@ -667,45 +667,6 @@ digestControlFile(ControlFileData *ControlFile, char *src, size_t size)
 }
 
 /*
- * Update the target's control file.
- */
-static void
-updateControlFile(ControlFileData *ControlFile)
-{
-	char		buffer[PG_CONTROL_FILE_SIZE];
-
-	/*
-	 * For good luck, apply the same static assertions as in backend's
-	 * WriteControlFile().
-	 */
-	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_MAX_SAFE_SIZE,
-					 "pg_control is too large for atomic disk writes");
-	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_FILE_SIZE,
-					 "sizeof(ControlFileData) exceeds PG_CONTROL_FILE_SIZE");
-
-	/* Recalculate CRC of control file */
-	INIT_CRC32C(ControlFile->crc);
-	COMP_CRC32C(ControlFile->crc,
-				(char *) ControlFile,
-				offsetof(ControlFileData, crc));
-	FIN_CRC32C(ControlFile->crc);
-
-	/*
-	 * Write out PG_CONTROL_FILE_SIZE bytes into pg_control by zero-padding
-	 * the excess over sizeof(ControlFileData), to avoid premature EOF related
-	 * errors when reading it.
-	 */
-	memset(buffer, 0, PG_CONTROL_FILE_SIZE);
-	memcpy(buffer, ControlFile, sizeof(ControlFileData));
-
-	open_target_file("global/pg_control", false);
-
-	write_target_range(buffer, 0, PG_CONTROL_FILE_SIZE);
-
-	close_target_file();
-}
-
-/*
  * Sync target data directory to ensure that modifications are safely on disk.
  *
  * We do this once, for the whole data directory, for performance reasons.  At
diff --git a/src/common/controldata_utils.c b/src/common/controldata_utils.c
index 6289a4343ad..71e67a2edaa 100644
--- a/src/common/controldata_utils.c
+++ b/src/common/controldata_utils.c
@@ -24,8 +24,10 @@
 #include <sys/stat.h>
 #include <fcntl.h>
 
+#include "access/xlog_internal.h"
 #include "catalog/pg_control.h"
 #include "common/controldata_utils.h"
+#include "common/file_perm.h"
 #include "port/pg_crc32c.h"
 #ifndef FRONTEND
 #include "storage/fd.h"
@@ -137,3 +139,95 @@ get_controlfile(const char *DataDir, const char *progname, bool *crc_ok_p)
 
 	return ControlFile;
 }
+
+/*
+ * update_controlfile()
+ *
+ * Update controlfile values with the contents given by caller.  The
+ * contents to write are included in "ControlFile".  Note that it is up
+ * to the caller to fsync the updated file, and to properly lock
+ * ControlFileLock when calling this routine in the backend.
+ */
+void
+update_controlfile(const char *DataDir, const char *progname,
+				   ControlFileData *ControlFile)
+{
+	int			fd;
+	char		buffer[PG_CONTROL_FILE_SIZE];
+	char		ControlFilePath[MAXPGPATH];
+
+	/*
+	 * Apply the same static assertions as in backend's WriteControlFile().
+	 */
+	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_MAX_SAFE_SIZE,
+					 "pg_control is too large for atomic disk writes");
+	StaticAssertStmt(sizeof(ControlFileData) <= PG_CONTROL_FILE_SIZE,
+					 "sizeof(ControlFileData) exceeds PG_CONTROL_FILE_SIZE");
+
+	/* Recalculate CRC of control file */
+	INIT_CRC32C(ControlFile->crc);
+	COMP_CRC32C(ControlFile->crc,
+				(char *) ControlFile,
+				offsetof(ControlFileData, crc));
+	FIN_CRC32C(ControlFile->crc);
+
+	/*
+	 * Write out PG_CONTROL_FILE_SIZE bytes into pg_control by zero-padding
+	 * the excess over sizeof(ControlFileData), to avoid premature EOF related
+	 * errors when reading it.
+	 */
+	memset(buffer, 0, PG_CONTROL_FILE_SIZE);
+	memcpy(buffer, ControlFile, sizeof(ControlFileData));
+
+	snprintf(ControlFilePath, sizeof(ControlFilePath), "%s/%s", DataDir, XLOG_CONTROL_FILE);
+
+#ifndef FRONTEND
+	if ((fd = OpenTransientFile(ControlFilePath, O_WRONLY | PG_BINARY)) == -1)
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not open file \"%s\": %m",
+						ControlFilePath)));
+#else
+	if ((fd = open(ControlFilePath, O_WRONLY | PG_BINARY,
+				   pg_file_create_mode)) == -1)
+	{
+		fprintf(stderr, _("%s: could not open file \"%s\": %s\n"),
+				progname, ControlFilePath, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+#endif
+
+	errno = 0;
+	if (write(fd, buffer, PG_CONTROL_FILE_SIZE) != PG_CONTROL_FILE_SIZE)
+	{
+		/* if write didn't set errno, assume problem is no disk space */
+		if (errno == 0)
+			errno = ENOSPC;
+
+#ifndef FRONTEND
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not write file \"%s\": %m",
+						ControlFilePath)));
+#else
+		fprintf(stderr, _("%s: could not write \"%s\": %s\n"),
+				progname, ControlFilePath, strerror(errno));
+		exit(EXIT_FAILURE);
+#endif
+	}
+
+#ifndef FRONTEND
+	if (CloseTransientFile(fd))
+		ereport(PANIC,
+				(errcode_for_file_access(),
+				 errmsg("could not close file \"%s\": %m",
+						ControlFilePath)));
+#else
+	if (close(fd) < 0)
+	{
+		fprintf(stderr, _("%s: could not close file \"%s\": %s\n"),
+				progname, ControlFilePath, strerror(errno));
+		exit(EXIT_FAILURE);
+	}
+#endif
+}
diff --git a/src/include/common/controldata_utils.h b/src/include/common/controldata_utils.h
index 0ffa2000fc2..95317ebacf2 100644
--- a/src/include/common/controldata_utils.h
+++ b/src/include/common/controldata_utils.h
@@ -12,6 +12,10 @@
 
 #include "catalog/pg_control.h"
 
-extern ControlFileData *get_controlfile(const char *DataDir, const char *progname, bool *crc_ok_p);
+extern ControlFileData *get_controlfile(const char *DataDir,
+										const char *progname,
+										bool *crc_ok_p);
+extern void update_controlfile(const char *DataDir, const char *progname,
+							   ControlFileData *ControlFile);
 
 #endif							/* COMMON_CONTROLDATA_UTILS_H */