From ed065aeb981a44e6325ce3a3ee96606dcf7f95ed Mon Sep 17 00:00:00 2001 From: Jens Axboe Date: Wed, 17 Jun 2020 15:00:04 -0600 Subject: [PATCH] io_uring: reap poll completions while waiting for refs to drop on exit [ Upstream commit 56952e91acc93ed624fe9da840900defb75f1323 ] If we're doing polled IO and end up having requests being submitted async, then completions can come in while we're waiting for refs to drop. We need to reap these manually, as nobody else will be looking for them. Break the wait into 1/20th of a second time waits, and check for done poll completions if we time out. Otherwise we can have done poll completions sitting in ctx->poll_list, which needs us to reap them but we're just waiting for them. Cc: stable@vger.kernel.org Signed-off-by: Jens Axboe Signed-off-by: Greg Kroah-Hartman --- fs/io_uring.c | 12 +++++++++++- 1 file changed, 11 insertions(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index 5e0c25d6a525e..72a740c252231 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -7404,7 +7404,17 @@ static void io_ring_exit_work(struct work_struct *work) if (ctx->rings) io_cqring_overflow_flush(ctx, true); - wait_for_completion(&ctx->completions[0]); + /* + * If we're doing polled IO and end up having requests being + * submitted async (out-of-line), then completions can come in while + * we're waiting for refs to drop. We need to reap these manually, + * as nobody else will be looking for them. + */ + while (!wait_for_completion_timeout(&ctx->completions[0], HZ/20)) { + io_iopoll_reap_events(ctx); + if (ctx->rings) + io_cqring_overflow_flush(ctx, true); + } io_ring_ctx_free(ctx); } -- 2.47.3