[PATCH -next] io_uring: Fix build error without CONFIG_EVENTFD

[Zhang Qilong <zhangqilong3@huawei.com>]

If CONFIG_IO_URING=y, CONFIG_EVENTFD=n, bulding fails:

io_uring/io_uring.c: In function ‘io_eventfd_ops’:
io_uring/io_uring.c:498:3: error: implicit declaration of function ‘eventfd_signal_mask’; did you mean ‘eventfd_signal’? [-Werror=implicit-function-declaration]
   eventfd_signal_mask(ev_fd->cq_ev_fd, 1, EPOLL_URING_WAKE);

This patch fixes that.

Fixes: 261187e66de3 ("io_uring: pass in EPOLL_URING_WAKE for eventfd signaling and wakeups")
Signed-off-by: Zhang Qilong <zhangqilong3@huawei.com>
---
 include/linux/eventfd.h | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/include/linux/eventfd.h b/include/linux/eventfd.h
index e849329ce1a8..6c541c9a2478 100644
--- a/include/linux/eventfd.h
+++ b/include/linux/eventfd.h
@@ -67,6 +67,12 @@ static inline int eventfd_signal(struct eventfd_ctx *ctx, int n)
 	return -ENOSYS;
 }
 
+static inline int eventfd_signal_mask(struct eventfd_ctx *ctx,
+				       __u64 n, unsigned mask)
+{
+	return -ENOSYS;
+}
+
 static inline void eventfd_ctx_put(struct eventfd_ctx *ctx)
 {
 
-- 
2.25.1