[PATCH AUTOSEL 6.0 23/34] io_uring: don't iopoll from io_ring_ctx_wait_and_kill()

Sasha Levin
2022-11-01T11:30:15Z

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

[ Upstream commit 02bac94bd8efd75f615ac7515dd2def75b43e5b9 ]

We should not be completing requests from a task context that has already
undergone io_uring cancellations, i.e. __io_uring_cancel(), as there are
some assumptions, e.g. around cached task refs draining. Remove
iopolling from io_ring_ctx_wait_and_kill() as it can be called later
after PF_EXITING is set with the last task_work run.

Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
Link: https://lore.kernel.org/r/7c03cc91455c4a1af49c6b9cbda4e57ea467aa11.1665891182.git.asml.silence@gmail.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
io_uring/io_uring.c | 13 +++++--------
1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/io_uring/io_uring.c b/io_uring/io_uring.c
index c5dd483a7de2..d29f397f095e 100644
--- a/io_uring/io_uring.c
+++ b/io_uring/io_uring.c
@@ -2653,15 +2653,12 @@ static __cold void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx)
io_poll_remove_all(ctx, NULL, true);
mutex_unlock(&ctx->uring_lock);

- /* failed during ring init, it couldn't have issued any requests */
- if (ctx->rings) {
+ /*
+ * If we failed setting up the ctx, we might not have any rings
+ * and therefore did not submit any requests
+ */
+ if (ctx->rings)
io_kill_timeouts(ctx, NULL, true);
- /* if we failed setting up the ctx, we might not have any rings */
- io_iopoll_try_reap_events(ctx);
- /* drop cached put refs after potentially doing completions */
- if (current->io_uring)
- io_uring_drop_tctx_refs(current);
- }

INIT_WORK(&ctx->exit_work, io_ring_exit_work);
/*
--
2.35.1