In io_uring_poll() we must flush overflowed CQ events before to check if there are CQ events available, to avoid missing events. We call the io_cqring_events() that checks and flushes any overflow and returns the number of CQ events available. We can avoid taking the 'uring_lock' since the flush is already protected by 'completion_lock'. Signed-off-by: Stefano Garzarella <sgarzare@xxxxxxxxxx> --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 77f22c3da30f..02e77e86abaf 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6301,7 +6301,7 @@ static __poll_t io_uring_poll(struct file *file, poll_table *wait) if (READ_ONCE(ctx->rings->sq.tail) - ctx->cached_sq_head != ctx->rings->sq_ring_entries) mask |= EPOLLOUT | EPOLLWRNORM; - if (READ_ONCE(ctx->rings->cq.head) != ctx->cached_cq_tail) + if (io_cqring_events(ctx, false)) mask |= EPOLLIN | EPOLLRDNORM; return mask; -- 2.24.1