From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-13.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 855E2C48BDF for ; Tue, 22 Jun 2021 18:45:25 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BEF261289 for ; Tue, 22 Jun 2021 18:45:25 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232597AbhFVSrk (ORCPT ); Tue, 22 Jun 2021 14:47:40 -0400 Received: from cloud48395.mywhc.ca ([173.209.37.211]:51176 "EHLO cloud48395.mywhc.ca" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230146AbhFVSri (ORCPT ); Tue, 22 Jun 2021 14:47:38 -0400 Received: from [173.237.58.148] (port=33328 helo=localhost) by cloud48395.mywhc.ca with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.94.2) (envelope-from ) id 1lvlOj-0002Tj-Nx; Tue, 22 Jun 2021 14:45:21 -0400 Date: Tue, 22 Jun 2021 11:45:20 -0700 From: Olivier Langlois To: Jens Axboe , Pavel Begunkov , io-uring@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Olivier Langlois Message-Id: <67c806d0bcf2e096c1b0c7e87bd5926c37231b87.1624387080.git.olivier@trillion01.com> In-Reply-To: References: Subject: [PATCH 1/2] io_uring: Fix race condition when sqp thread goes to sleep X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - cloud48395.mywhc.ca X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - trillion01.com X-Get-Message-Sender-Via: cloud48395.mywhc.ca: authenticated_id: olivier@trillion01.com X-Authenticated-Sender: cloud48395.mywhc.ca: olivier@trillion01.com X-Source: X-Source-Args: X-Source-Dir: Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org If an asynchronous completion happens before the task is preparing itself to wait and set its state to TASK_INTERRUPTABLE, the completion will not wake up the sqp thread. Signed-off-by: Olivier Langlois --- fs/io_uring.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/fs/io_uring.c b/fs/io_uring.c index fc8637f591a6..02f789e07d4c 100644 --- a/fs/io_uring.c +++ b/fs/io_uring.c @@ -6902,7 +6902,7 @@ static int io_sq_thread(void *data) } prepare_to_wait(&sqd->wait, &wait, TASK_INTERRUPTIBLE); - if (!io_sqd_events_pending(sqd)) { + if (!io_sqd_events_pending(sqd) && !current->task_works) { needs_sched = true; list_for_each_entry(ctx, &sqd->ctx_list, sqd_list) { io_ring_set_wakeup_flag(ctx); -- 2.32.0