io_uring: trigger eventfd for IOPOLL

Make sure io_iopoll_complete() tries to wake up eventfd, which currently
is skipped together with io_cqring_ev_posted() for non-SQPOLL IOPOLL.

Add an iopoll version of io_cqring_ev_posted(), duplicates a bit of
code, but they actually use different sets of wait queues may be for
better.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 27a8c226abf8c41a5227c6ec2b647abb2dfcb37b..91e517ad1421c0ff49801ddcc37c70ba16c62d4c 100644 (file)
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -1713,6 +1713,16 @@ static void io_cqring_ev_posted(struct io_ring_ctx *ctx)
                eventfd_signal(ctx->cq_ev_fd, 1);
 }
 
+static void io_cqring_ev_posted_iopoll(struct io_ring_ctx *ctx)
+{
+       if (ctx->flags & IORING_SETUP_SQPOLL) {
+               if (waitqueue_active(&ctx->wait))
+                       wake_up(&ctx->wait);
+       }
+       if (io_should_trigger_evfd(ctx))
+               eventfd_signal(ctx->cq_ev_fd, 1);
+}
+
 /* Returns true if there are no backlogged entries after the flush */
 static bool __io_cqring_overflow_flush(struct io_ring_ctx *ctx, bool force,
                                       struct task_struct *tsk,
@@ -2428,8 +2438,7 @@ static void io_iopoll_complete(struct io_ring_ctx *ctx, unsigned int *nr_events,
        }
 
        io_commit_cqring(ctx);
-       if (ctx->flags & IORING_SETUP_SQPOLL)
-               io_cqring_ev_posted(ctx);
+       io_cqring_ev_posted_iopoll(ctx);
        io_req_free_batch_finish(ctx, &rb);
 
        if (!list_empty(&again))