[PATCH v2 3/4] io_uring: tweak iopoll CQE_SKIP event counting

[Pavel Begunkov <asml.silence@gmail.com>]

When iopolling the userspace specifies the minimum number of "events" it
expects. Previously, we had one CQE per request, so the definition of
an "event" was unequivocal, but that's not more the case anymore with
REQ_F_CQE_SKIP.

Currently it counts the number of completed requests, replace it with
the number of posted CQEs. This allows users of the "one CQE per link"
scheme to wait for all N links in a single syscall, which is not
possible without the patch and requires extra context switches.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
---
 fs/io_uring.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 64add8260abb..ea7a0daa0b3b 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -2538,10 +2538,10 @@ static int io_do_iopoll(struct io_ring_ctx *ctx, bool force_nonspin)
 		/* order with io_complete_rw_iopoll(), e.g. ->result updates */
 		if (!smp_load_acquire(&req->iopoll_completed))
 			break;
+		if (unlikely(req->flags & REQ_F_CQE_SKIP))
+			continue;
 
-		if (!(req->flags & REQ_F_CQE_SKIP))
-			__io_fill_cqe(ctx, req->user_data, req->result,
-				      io_put_kbuf(req));
+		__io_fill_cqe(ctx, req->user_data, req->result, io_put_kbuf(req));
 		nr_events++;
 	}
 
-- 
2.34.0