From db9ff821a2baf396715ee8d1615e7b83da34bd8b Mon Sep 17 00:00:00 2001
From: Christian Prochaska <christian.prochaska@genode-labs.com>
Date: Fri, 18 Jan 2019 15:42:32 +0100
Subject: [PATCH] libc: sync 'listen' socket fs control file

Fixes #3124
---
 repos/libports/src/lib/libc/socket_fs_plugin.cc | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/repos/libports/src/lib/libc/socket_fs_plugin.cc b/repos/libports/src/lib/libc/socket_fs_plugin.cc
index fa0366ed9a..24f21e76b1 100644
--- a/repos/libports/src/lib/libc/socket_fs_plugin.cc
+++ b/repos/libports/src/lib/libc/socket_fs_plugin.cc
@@ -700,6 +700,10 @@ extern "C" int socket_fs_listen(int libc_fd, int backlog)
 	int const n   = write(context->listen_fd(), buf, len);
 	if (n != len) return Errno(EOPNOTSUPP);
 
+	/* sync to block for write completion */
+	int const res = fsync(context->listen_fd());
+	if (res != 0) return res;
+
 	context->state(Context::ACCEPT_ONLY);
 	return 0;
 }