[PATCH AUTOSEL 5.7 258/274] io_uring: fix overflowed reqs cancellation

Sasha Levin
2020-06-09T00:45:49Z

From: Pavel Begunkov <asml.silence@gmail.com>

[ Upstream commit 7b53d59859bc932b37895d2d37388e7fa29af7a5 ]

Overflowed requests in io_uring_cancel_files() should be shed only of
inflight and overflowed refs. All other left references are owned by
someone else.

If refcount_sub_and_test() fails, it will go further and put put extra
ref, don't do that. Also, don't need to do io_wq_cancel_work()
for overflowed reqs, they will be let go shortly anyway.

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 | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/fs/io_uring.c b/fs/io_uring.c
index dd90c3fcd4f5..4038ed0a5c39 100644
--- a/fs/io_uring.c
+++ b/fs/io_uring.c
@@ -7467,10 +7467,11 @@ static void io_uring_cancel_files(struct io_ring_ctx *ctx,
finish_wait(&ctx->inflight_wait, &wait);
continue;
}
+ } else {
+ io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
+ io_put_req(cancel_req);
}

- io_wq_cancel_work(ctx->io_wq, &cancel_req->work);
- io_put_req(cancel_req);
schedule();
finish_wait(&ctx->inflight_wait, &wait);
}
--
2.25.1