io_uring: fix missing set of EPOLLONESHOT for CQ ring overflow

We should set EPOLLONESHOT if cqring_fill_event() returns false since
io_poll_add() decides to put req or not by it.

Fixes: 63417da8395c ("io_uring: terminate multishot poll for CQ ring overflow")
Signed-off-by: Hao Xu <haoxu@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210922101238.7177-3-haoxu@linux.alibaba.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 43530aae618062f5fafe36b92fafb4293c0faf82..ac0c06d5c6298732e67a24630a4137c6e337e4ac 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -5337,8 +5337,10 @@ static bool __io_poll_complete(struct io_kiocb *req, __poll_t mask)
        }
        if (req->poll.events & EPOLLONESHOT)
                flags = 0;
-       if (!io_cqring_fill_event(ctx, req->user_data, error, flags))
+       if (!io_cqring_fill_event(ctx, req->user_data, error, flags)) {
+               req->poll.events |= EPOLLONESHOT;
                flags = 0;
+       }
        if (flags & IORING_CQE_F_MORE)
                ctx->cq_extra++;