/* can use bio alloc cache */
 #define IOCB_ALLOC_CACHE       (1 << 21)
 
+/* for use in trace events */
+#define TRACE_IOCB_STRINGS \
+       { IOCB_HIPRI,           "HIPRI" }, \
+       { IOCB_DSYNC,           "DSYNC" }, \
+       { IOCB_SYNC,            "SYNC" }, \
+       { IOCB_NOWAIT,          "NOWAIT" }, \
+       { IOCB_APPEND,          "APPEND" }, \
+       { IOCB_EVENTFD,         "EVENTFD"}, \
+       { IOCB_DIRECT,          "DIRECT" }, \
+       { IOCB_WRITE,           "WRITE" }, \
+       { IOCB_WAITQ,           "WAITQ" }, \
+       { IOCB_NOIO,            "NOIO" }, \
+       { IOCB_ALLOC_CACHE,     "ALLOC_CACHE" }
+
 struct kiocb {
        struct file             *ki_filp;
        loff_t                  ki_pos;