From: Pavel Begunkov asml.silence@gmail.com
[ Upstream commit f6d54255f4235448d4bbe442362d4caa62da97d5 ]
io_sq_thread_finish() is called in io_ring_ctx_free(), so SQPOLL task is potentially running submitting new requests. It's not a disaster because of using a "try" variant of percpu_ref_get, but is far from nice.
Remove ctx from the sqd ctx list earlier, before cancellation loop, so SQPOLL can't find it and so won't submit new requests.
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 | 8 ++++++++ 1 file changed, 8 insertions(+)
diff --git a/fs/io_uring.c b/fs/io_uring.c index 381f82ebd282..aaf9b5d49c17 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -8800,6 +8800,14 @@ static void io_ring_ctx_wait_and_kill(struct io_ring_ctx *ctx) __io_cqring_overflow_flush(ctx, true, NULL, NULL); mutex_unlock(&ctx->uring_lock);
+ /* prevent SQPOLL from submitting new requests */ + if (ctx->sq_data) { + io_sq_thread_park(ctx->sq_data); + list_del_init(&ctx->sqd_list); + io_sqd_update_thread_idle(ctx->sq_data); + io_sq_thread_unpark(ctx->sq_data); + } + io_kill_timeouts(ctx, NULL, NULL); io_poll_remove_all(ctx, NULL, NULL);