From 150e8f78bf78213a7ebaed38e96ebcf2d2a7bfed Mon Sep 17 00:00:00 2001
From: Max Kellermann <max.kellermann@gmail.com>
Date: Thu, 14 Jul 2022 18:31:58 +0200
Subject: [PATCH] io/FileOutputStream: use fsync() if fdatasync() is
 unavailable

Fixes the macOS build which apparently doesn't implement the POSIX
function fdatasync().
---
 src/io/FileOutputStream.cxx | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/src/io/FileOutputStream.cxx b/src/io/FileOutputStream.cxx
index ec573b5f3..a7cd50fe3 100644
--- a/src/io/FileOutputStream.cxx
+++ b/src/io/FileOutputStream.cxx
@@ -252,7 +252,12 @@ FileOutputStream::Sync()
 {
 	assert(IsDefined());
 
-	if (fdatasync(fd.Get()) < 0)
+#ifdef __linux__
+	const bool success = fdatasync(fd.Get()) == 0;
+#else
+	const bool success = fsync(fd.Get()) == 0;
+#endif
+	if (!success)
 		throw FormatErrno("Failed to sync %s", GetPath().c_str());
 }