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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Pavel Begunkov <asml.silence@gmail.com>,
        Jens Axboe <axboe@kernel.dk>, Sasha Levin <sashal@kernel.org>
Subject: [PATCH 5.7 119/393] io_uring: fix stalled deferred requests
Date:   Mon, 17 Aug 2020 17:12:49 +0200
Message-Id: <20200817143825.387573280@linuxfoundation.org>
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From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit dd9dfcdf5a603680458f5e7b0d2273c66e5417db ]

Always do io_commit_cqring() after completing a request, even if it was
accounted as overflowed on the CQ side. Failing to do that may lead to
not to pushing deferred requests when needed, and so stalling the whole
ring.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/io_uring.c | 1 +
 1 file changed, 1 insertion(+)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index c212af69c15b4..06a093da872f8 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7581,6 +7581,7 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
 			}
 			WRITE_ONCE(ctx->rings->cq_overflow,
 				atomic_inc_return(&ctx->cached_cq_overflow));
+			io_commit_cqring(ctx);
 			spin_unlock_irq(&ctx->completion_lock);
 
 			/*
-- 
2.25.1