From 24d38dcce407cc6c2e76efd127a27db89cf26203 Mon Sep 17 00:00:00 2001
From: Hao Xu <haoxu@linux.alibaba.com>
Date: Wed, 22 Sep 2021 18:12:37 +0800
Subject: [PATCH] io_uring: fix missing set of EPOLLONESHOT for CQ ring overflow
Git-commit: a62682f92eedb41c1cd8290fa875a4b85624fb9a
Patch-mainline: v5.15-rc3
References: stable-5.14.9

[ Upstream commit a62682f92eedb41c1cd8290fa875a4b85624fb9a ]

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

Fixes: 5082620fb2ca ("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>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Acked-by: Takashi Iwai <tiwai@suse.de>

---
 fs/io_uring.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index 27a1c813f1e1..739e58ccc982 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -4968,8 +4968,10 @@ 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++;
 
-- 
2.26.2