io_uring: only force async punt if poll based retry can't handle it

We do blocking retry from our poll handler, if the file supports polled
notifications. Only mark the request as needing an async worker if we
can't poll for it.
Signed-off-by: Jens Axboe <axboe@kernel.dk>

fs/io_uring.c

@@ -2604,7 +2604,8 @@ static int io_read(struct io_kiocb *req, bool force_nonblock)
 			if (ret)
 				goto out_free;
 			/* any defer here is final, must blocking retry */
-			if (!(req->flags & REQ_F_NOWAIT))
+			if (!(req->flags & REQ_F_NOWAIT) &&
+			    !file_can_poll(req->file))
 				req->flags |= REQ_F_MUST_PUNT;
 			return -EAGAIN;
 		}
@@ -2726,6 +2727,7 @@ static int io_write(struct io_kiocb *req, bool force_nonblock)
 			if (ret)
 				goto out_free;
 			/* any defer here is final, must blocking retry */
+			if (!file_can_poll(req->file))
 				req->flags |= REQ_F_MUST_PUNT;
 			return -EAGAIN;
 		}