libaio engine: proper return value checking

Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/engines/libaio.c b/engines/libaio.c
index bd702e30f132ab082a69add4b729ca9e6dd6d9b5..bc9c42877fdaaadf98d1c5ab51520c4e85d3903b 100644 (file)
--- a/engines/libaio.c
+++ b/engines/libaio.c
@@ -42,8 +42,21 @@ static int fio_libaio_prep(struct thread_data fio_unused *td, struct io_u *io_u)
 static struct io_u *fio_libaio_event(struct thread_data *td, int event)
 {
        struct libaio_data *ld = td->io_ops->data;
+       struct io_event *ev;
+       struct io_u *io_u;
 
-       return ev_to_iou(ld->aio_events + event);
+       ev = ld->aio_events + event;
+       io_u = ev_to_iou(ev);
+
+       if (ev->res != io_u->xfer_buflen) {
+               if (ev->res > io_u->xfer_buflen)
+                       io_u->error = -ev->res;
+               else
+                       io_u->resid = io_u->xfer_buflen - ev->res;
+       } else
+               io_u->error = 0;
+
+       return io_u;
 }
 
 static int fio_libaio_getevents(struct thread_data *td, int min, int max,