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=-16.8 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,UNPARSEABLE_RELAY,USER_AGENT_GIT autolearn=ham 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 30168C4332F for ; Sat, 11 Sep 2021 19:41:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1115761152 for ; Sat, 11 Sep 2021 19:41:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232047AbhIKTmO (ORCPT ); Sat, 11 Sep 2021 15:42:14 -0400 Received: from out30-131.freemail.mail.aliyun.com ([115.124.30.131]:50734 "EHLO out30-131.freemail.mail.aliyun.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233742AbhIKTmN (ORCPT ); Sat, 11 Sep 2021 15:42:13 -0400 X-Alimail-AntiSpam: AC=PASS;BC=-1|-1;BR=01201311R201e4;CH=green;DM=||false|;DS=||;FP=0|-1|-1|-1|0|-1|-1|-1;HT=e01e04426;MF=haoxu@linux.alibaba.com;NM=1;PH=DS;RN=4;SR=0;TI=SMTPD_---0Uo.lhDo_1631389252; Received: from e18g09479.et15sqa.tbsite.net(mailfrom:haoxu@linux.alibaba.com fp:SMTPD_---0Uo.lhDo_1631389252) by smtp.aliyun-inc.com(127.0.0.1); Sun, 12 Sep 2021 03:40:59 +0800 From: Hao Xu To: Jens Axboe Cc: io-uring@vger.kernel.org, Pavel Begunkov , Joseph Qi Subject: [PATCH 3/4] io-wq: fix worker->refcount when creating worker in work exit Date: Sun, 12 Sep 2021 03:40:51 +0800 Message-Id: <20210911194052.28063-4-haoxu@linux.alibaba.com> X-Mailer: git-send-email 2.24.4 In-Reply-To: <20210911194052.28063-1-haoxu@linux.alibaba.com> References: <20210911194052.28063-1-haoxu@linux.alibaba.com> MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org We may enter the worker creation path from io_worker_exit(), and refcount is already zero, which causes definite failure of worker creation. io_worker_exit ref = 0 ->io_wqe_dec_running ->io_queue_worker_create ->io_worker_get failure since ref is 0 Signed-off-by: Hao Xu --- fs/io-wq.c | 2 ++ 1 file changed, 2 insertions(+) diff --git a/fs/io-wq.c b/fs/io-wq.c index 0e1288a549eb..75e79571bdfd 100644 --- a/fs/io-wq.c +++ b/fs/io-wq.c @@ -188,7 +188,9 @@ static void io_worker_exit(struct io_worker *worker) list_del_rcu(&worker->all_list); acct->nr_workers--; preempt_disable(); + refcount_set(&worker->ref, 1); io_wqe_dec_running(worker); + refcount_set(&worker->ref, 0); worker->flags = 0; current->flags &= ~PF_IO_WORKER; preempt_enable(); -- 2.24.4