include: move qemu_fdatasync() to osdep

Move QEMU-specific code to util/osdep.c, so cutils can become a common
subproject.

Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-Id: <20220420132624.2439741-22-marcandre.lureau@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/util/osdep.c b/util/osdep.c
index 1ea2398686..c7aec36f22 100644
--- a/util/osdep.c
+++ b/util/osdep.c
@@ -607,3 +607,19 @@ writev(int fd, const struct iovec *iov, int iov_cnt)
     return readv_writev(fd, iov, iov_cnt, true);
 }
 #endif
+
+/*
+ * Make sure data goes on disk, but if possible do not bother to
+ * write out the inode just for timestamp updates.
+ *
+ * Unfortunately even in 2009 many operating systems do not support
+ * fdatasync and have to fall back to fsync.
+ */
+int qemu_fdatasync(int fd)
+{
+#ifdef CONFIG_FDATASYNC
+    return fdatasync(fd);
+#else
+    return fsync(fd);
+#endif
+}