4 files changed, 2 insertions, 18 deletions
diff --git a/src/include/access/xlogdefs.h b/src/include/access/xlogdefs.h
index 810cd1fd86a..49e581925c9 100644
--- a/src/include/access/xlogdefs.h
+++ b/src/include/access/xlogdefs.h
@@ -67,8 +67,7 @@ typedef uint16 RepOriginId;
 /*
  * This chunk of hackery attempts to determine which file sync methods
  * are available on the current platform, and to choose an appropriate
- * default method.  We assume that fsync() is always available, and that
- * configure determined whether fdatasync() is.
+ * default method.
  *
  * Note that we define our own O_DSYNC on Windows, but not O_SYNC.
  */
@@ -76,10 +75,8 @@ typedef uint16 RepOriginId;
 #define DEFAULT_SYNC_METHOD		PLATFORM_DEFAULT_SYNC_METHOD
 #elif defined(O_DSYNC) && (!defined(O_SYNC) || O_DSYNC != O_SYNC)
 #define DEFAULT_SYNC_METHOD		SYNC_METHOD_OPEN_DSYNC
-#elif defined(HAVE_FDATASYNC)
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FDATASYNC
 #else
-#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FSYNC
+#define DEFAULT_SYNC_METHOD		SYNC_METHOD_FDATASYNC
 #endif
 
 #endif							/* XLOG_DEFS_H */
diff --git a/src/include/pg_config.h.in b/src/include/pg_config.h.in
index 6505a842118..2a0d08d10f5 100644
--- a/src/include/pg_config.h.in
+++ b/src/include/pg_config.h.in
@@ -170,9 +170,6 @@
 /* Define to 1 if you have the `explicit_bzero' function. */
 #undef HAVE_EXPLICIT_BZERO
 
-/* Define to 1 if you have the `fdatasync' function. */
-#undef HAVE_FDATASYNC
-
 /* Define to 1 if fseeko (and presumably ftello) exists and is declared. */
 #undef HAVE_FSEEKO
 
diff --git a/src/include/port/freebsd.h b/src/include/port/freebsd.h
index 2e2e749a6b6..0e3fde55d6d 100644
--- a/src/include/port/freebsd.h
+++ b/src/include/port/freebsd.h
@@ -5,6 +5,4 @@
  * would prefer open_datasync on FreeBSD 13+, but that is not a good choice on
  * many systems.
  */
-#ifdef HAVE_FDATASYNC
 #define PLATFORM_DEFAULT_SYNC_METHOD	SYNC_METHOD_FDATASYNC
-#endif
diff --git a/src/include/port/win32_port.h b/src/include/port/win32_port.h
index 336e11b3ba4..0eaa97561a0 100644
--- a/src/include/port/win32_port.h
+++ b/src/include/port/win32_port.h
@@ -83,14 +83,6 @@
 #define HAVE_FSYNC_WRITETHROUGH
 #define FSYNC_WRITETHROUGH_IS_FSYNC
 
-/*
- * We have a replacement for fdatasync() in src/port/fdatasync.c, which is
- * unconditionally used by MSVC and Mingw builds.
- */
-#ifndef HAVE_FDATASYNC
-#define HAVE_FDATASYNC
-#endif
-
 #define USES_WINSOCK
 
 /*