[PATCH liburing 1/3] preseve wait_nr if SETUP_IOPOLL is set

[Bijan Mottahedeh <bijan.mottahedeh@oracle.com>]

When SETUP_IOPOLL is set, __sys_io_uring_enter() must be called to reap
new completions but the call won't be made if both wait_nr and submit
are zero, so preserve wait_nr.

Signed-off-by: Bijan Mottahedeh <bijan.mottahedeh@oracle.com>
---
 src/queue.c | 9 ++++++++-
 1 file changed, 8 insertions(+), 1 deletion(-)

diff --git a/src/queue.c b/src/queue.c
index 14a0777..c7473c0 100644
--- a/src/queue.c
+++ b/src/queue.c
@@ -60,7 +60,14 @@ int __io_uring_get_cqe(struct io_uring *ring, struct io_uring_cqe **cqe_ptr,
 			err = -errno;
 		} else if (ret == (int)submit) {
 			submit = 0;
-			wait_nr = 0;
+			/*
+			 * When SETUP_IOPOLL is set, __sys_io_uring enter()
+			 * must be called to reap new completions but the call
+			 * won't be made if both wait_nr and submit are zero
+			 * so preserve wait_nr.
+			 */
+			if (!(ring->flags & IORING_SETUP_IOPOLL))
+				wait_nr = 0;
 		} else {
 			submit -= ret;
 		}
-- 
1.8.3.1