3 files changed, 16 insertions, 1 deletions
diff --git a/erts/emulator/drivers/common/erl_efile.h b/erts/emulator/drivers/common/erl_efile.h
index 5387f75efc..95c036db8f 100644
--- a/erts/emulator/drivers/common/erl_efile.h
+++ b/erts/emulator/drivers/common/erl_efile.h
@@ -34,6 +34,7 @@
 #define EFILE_COMPRESSED 	8
 #define EFILE_MODE_EXCL        16
 #define EFILE_NO_TRUNCATE      32 /* Special for reopening on VxWorks */
+#define EFILE_MODE_SYNC        64
 
 /*
  * Seek modes for efile_seek().
diff --git a/erts/emulator/drivers/unix/unix_efile.c b/erts/emulator/drivers/unix/unix_efile.c
index 55539b44dd..8ffc05da99 100644
--- a/erts/emulator/drivers/unix/unix_efile.c
+++ b/erts/emulator/drivers/unix/unix_efile.c
@@ -405,6 +405,15 @@ efile_openfile(Efile_error* errInfo,	/* Where to return error codes. */
 	mode |= O_EXCL;
     }
 
+    if (flags & EFILE_MODE_SYNC) {
+#ifdef O_SYNC
+	mode |= O_SYNC;
+#else
+	errno = ENOTSUP;
+	return check_error(-1, errInfo);
+#endif
+    }
+
     fd = open(name, mode, FILE_MODE);
 
     if (!check_error(fd, errInfo))
diff --git a/erts/emulator/drivers/win32/win_efile.c b/erts/emulator/drivers/win32/win_efile.c
index 319065f57b..d693d7d593 100644
--- a/erts/emulator/drivers/win32/win_efile.c
+++ b/erts/emulator/drivers/win32/win_efile.c
@@ -698,6 +698,7 @@ efile_openfile(Efile_error* errInfo,		/* Where to return error codes. */
     HANDLE fd;			/* Handle to open file. */
     DWORD access;		/* Access mode: GENERIC_READ, GENERIC_WRITE. */
     DWORD crFlags;
+    DWORD flagsAndAttrs = FILE_ATTRIBUTE_NORMAL;
     WCHAR *wname = (WCHAR *) name;
 
     switch (flags & (EFILE_MODE_READ|EFILE_MODE_WRITE)) {
@@ -719,6 +720,10 @@ efile_openfile(Efile_error* errInfo,		/* Where to return error codes. */
 	return 0;
     }
 
+    if (flags & EFILE_MODE_SYNC) {
+        flagsAndAttrs = FILE_FLAG_WRITE_THROUGH;
+    }
+
     if (flags & EFILE_MODE_APPEND) {
 	crFlags = OPEN_ALWAYS;
     }
@@ -727,7 +732,7 @@ efile_openfile(Efile_error* errInfo,		/* Where to return error codes. */
     }
     fd = CreateFileW(wname, access,
 		    FILE_SHARE_FLAGS,
-		    NULL, crFlags, FILE_ATTRIBUTE_NORMAL, NULL);
+		    NULL, crFlags, flagsAndAttrs, NULL);
 
     /*
      * Check for errors.