added in linux kernel commit 73fa7547c70b32cc69685f79be31135797734eb6. this is added now as a prerequisite for fixing pwrite/pwritev behavior for O_APPEND files.
@@ -46,6 +46,7 @@ ssize_t pwritev2 (int, const struct iovec *, int, off_t, int);
#define RWF_SYNC 0x00000004
#define RWF_NOWAIT 0x00000008
#define RWF_APPEND 0x00000010
+#define RWF_NOAPPEND 0x00000020
#endif
#ifdef __cplusplus