[PATCH AUTOSEL 5.7 58/60] io_uring: fix stalled deferred requests

Sasha Levin
2020-08-10T19:26:29Z

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 d04fede20acb8..5d33c05de02e5 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7575,6 +7575,7 @@ 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