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>

include/qemu/cutils.h

@@ -129,7 +129,6 @@ static inline const char *qemu_strchrnul(const char *s, int c)
 const char *qemu_strchrnul(const char *s, int c);
 #endif
 time_t mktimegm(struct tm *tm);
-int qemu_fdatasync(int fd);
 int qemu_parse_fd(const char *param);
 int qemu_strtoi(const char *nptr, const char **endptr, int base,
                 int *result);

include/qemu/osdep.h

@@ -641,6 +641,8 @@ static inline void qemu_reset_optind(void)
 #endif
 }
 
+int qemu_fdatasync(int fd);
+
 /**
  * Sync changes made to the memory mapped file back to the backing
  * storage. For POSIX compliant systems this will fallback

util/cutils.c

@@ -144,22 +144,6 @@ time_t mktimegm(struct tm *tm)
     return t;
 }
 
-/*
- * 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
-}
-
 static int64_t suffix_mul(char suffix, int64_t unit)
 {
     switch (qemu_toupper(suffix)) {

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
+}