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=-17.5 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 B69B9C433DB for ; Mon, 21 Dec 2020 04:54:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7247822B37 for ; Mon, 21 Dec 2020 04:54:54 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728372AbgLUEyj (ORCPT ); Sun, 20 Dec 2020 23:54:39 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38634 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728367AbgLUEyi (ORCPT ); Sun, 20 Dec 2020 23:54:38 -0500 Received: from mail-wm1-x32a.google.com (mail-wm1-x32a.google.com [IPv6:2a00:1450:4864:20::32a]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id BB86AC0613D3; Sun, 20 Dec 2020 20:53:57 -0800 (PST) Received: by mail-wm1-x32a.google.com with SMTP id a6so8699777wmc.2; Sun, 20 Dec 2020 20:53:57 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:from:to:cc:references:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=lX32/8Xuph8eHK0o6FlvjN3ViQPYOiihsp675ptbfAw=; b=TqiXC4GG8qMgAuFnnSaFFBni/YcP/e7+y876Ug82Ki1OWZ0Kf7ZznRilzfcXqgPQIT WuDzJoa4yQXBiWW61LM52ms1gOIIHTOSkbxttTu4SQqi+/3ahRzNVjY0KpX/E0wMnU6x YslHHkHyzY5mDowedT1deD+5n9QOoUjCtjo4H9rdUmHDYqyFaPpaYbDBxBOooRQULl+Z qVDi0ixfIoZT4jfWQXX5ChAMPpkfqgpEwaSvGAfrQ5CCCyI7PJkmAQO/P5nuK/SwPWOG Rsbfr7gskb5P2LCX9gkUOpnYMjzrMORo8bSGu3CogcXprMPiKLaSGp6Y/h/H2NE8Carj FEgA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:from:to:cc:references:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=lX32/8Xuph8eHK0o6FlvjN3ViQPYOiihsp675ptbfAw=; b=sIo3dzFITOLeIkdlelFT0yOyYU8vvnaBKNwCDAppGvZR91Sd+TTn9rtR/aJQiZh2t0 v36PeQVFJ2bJss9ga/izwLiUc3X8uyHWtejKCsbtPmeQ+bzQVNy28iL0XxBAPbO4jJ6u A8EMXNaoo/G8G07RTe4PYozG+YYAvKDILOhOg3wdSIhg4SEoZSjg+aT3PmNzOzZOBom6 7hzvCavfSl+/j3kw9pbrWkW8ypIoaxqcZald3dSvqTLiDDKdt3tashcNgAEie/ByqOZT EIgdmCVL6SZYA1tDOMVBkrxGsfOobiKA1ItZjIf/yI713D6FU7bucc0gk2BHDG8+snZh ALlQ== X-Gm-Message-State: AOAM530qDnrLFGKWDkevLjXZkcytHr4oPYnSxIYNme1juai8dR4r2CV6 MVdOTcc82CIR5B9nC7S5PCoHL+u97kXDXw== X-Google-Smtp-Source: ABdhPJxTZliArfzYy9vO3j/qg6/aPevSm9akngxStZgZbAek13d+gqEq+mShTQGqsY3qng6y2mVFlQ== X-Received: by 2002:a1c:2b05:: with SMTP id r5mr13053926wmr.179.1608491906090; Sun, 20 Dec 2020 11:18:26 -0800 (PST) Received: from [192.168.8.142] ([85.255.237.164]) by smtp.gmail.com with ESMTPSA id r7sm15802727wmh.2.2020.12.20.11.18.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sun, 20 Dec 2020 11:18:25 -0800 (PST) Subject: Re: [PATCH 1/1] io_uring: actively cancel poll/timeouts on exit From: Pavel Begunkov To: Jens Axboe , io-uring@vger.kernel.org Cc: stable@vger.kernel.org, Josef , Dmitry Kadashev References: Autocrypt: addr=asml.silence@gmail.com; prefer-encrypt=mutual; keydata= mQINBFmKBOQBEAC76ZFxLAKpDw0bKQ8CEiYJRGn8MHTUhURL02/7n1t0HkKQx2K1fCXClbps bdwSHrhOWdW61pmfMbDYbTj6ZvGRvhoLWfGkzujB2wjNcbNTXIoOzJEGISHaPf6E2IQx1ik9 6uqVkK1OMb7qRvKH0i7HYP4WJzYbEWVyLiAxUj611mC9tgd73oqZ2pLYzGTqF2j6a/obaqha +hXuWTvpDQXqcOZJXIW43atprH03G1tQs7VwR21Q1eq6Yvy2ESLdc38EqCszBfQRMmKy+cfp W3U9Mb1w0L680pXrONcnlDBCN7/sghGeMHjGKfNANjPc+0hzz3rApPxpoE7HC1uRiwC4et83 CKnncH1l7zgeBT9Oa3qEiBlaa1ZCBqrA4dY+z5fWJYjMpwI1SNp37RtF8fKXbKQg+JuUjAa9 Y6oXeyEvDHMyJYMcinl6xCqCBAXPHnHmawkMMgjr3BBRzODmMr+CPVvnYe7BFYfoajzqzq+h EyXSl3aBf0IDPTqSUrhbmjj5OEOYgRW5p+mdYtY1cXeK8copmd+fd/eTkghok5li58AojCba jRjp7zVOLOjDlpxxiKhuFmpV4yWNh5JJaTbwCRSd04sCcDNlJj+TehTr+o1QiORzc2t+N5iJ NbILft19Izdn8U39T5oWiynqa1qCLgbuFtnYx1HlUq/HvAm+kwARAQABtDFQYXZlbCBCZWd1 bmtvdiAoc2lsZW5jZSkgPGFzbWwuc2lsZW5jZUBnbWFpbC5jb20+iQJOBBMBCAA4FiEE+6Ju PTjTbx479o3OWt5b1Glr+6UFAlmKBOQCGwMFCwkIBwIGFQgJCgsCBBYCAwECHgECF4AACgkQ Wt5b1Glr+6WxZA//QueaKHzgdnOikJ7NA/Vq8FmhRlwgtP0+E+w93kL+ZGLzS/cUCIjn2f4Q Mcutj2Neg0CcYPX3b2nJiKr5Vn0rjJ/suiaOa1h1KzyNTOmxnsqE5fmxOf6C6x+NKE18I5Jy xzLQoktbdDVA7JfB1itt6iWSNoOTVcvFyvfe5ggy6FSCcP+m1RlR58XxVLH+qlAvxxOeEr/e aQfUzrs7gqdSd9zQGEZo0jtuBiB7k98t9y0oC9Jz0PJdvaj1NZUgtXG9pEtww3LdeXP/TkFl HBSxVflzeoFaj4UAuy8+uve7ya/ECNCc8kk0VYaEjoVrzJcYdKP583iRhOLlZA6HEmn/+Gh9 4orG67HNiJlbFiW3whxGizWsrtFNLsSP1YrEReYk9j1SoUHHzsu+ZtNfKuHIhK0sU07G1OPN 2rDLlzUWR9Jc22INAkhVHOogOcc5ajMGhgWcBJMLCoi219HlX69LIDu3Y34uIg9QPZIC2jwr 24W0kxmK6avJr7+n4o8m6sOJvhlumSp5TSNhRiKvAHB1I2JB8Q1yZCIPzx+w1ALxuoWiCdwV M/azguU42R17IuBzK0S3hPjXpEi2sK/k4pEPnHVUv9Cu09HCNnd6BRfFGjo8M9kZvw360gC1 reeMdqGjwQ68o9x0R7NBRrtUOh48TDLXCANAg97wjPoy37dQE7e5Ag0EWYoE5AEQAMWS+aBV IJtCjwtfCOV98NamFpDEjBMrCAfLm7wZlmXy5I6o7nzzCxEw06P2rhzp1hIqkaab1kHySU7g dkpjmQ7Jjlrf6KdMP87mC/Hx4+zgVCkTQCKkIxNE76Ff3O9uTvkWCspSh9J0qPYyCaVta2D1 Sq5HZ8WFcap71iVO1f2/FEHKJNz/YTSOS/W7dxJdXl2eoj3gYX2UZNfoaVv8OXKaWslZlgqN jSg9wsTv1K73AnQKt4fFhscN9YFxhtgD/SQuOldE5Ws4UlJoaFX/yCoJL3ky2kC0WFngzwRF Yo6u/KON/o28yyP+alYRMBrN0Dm60FuVSIFafSqXoJTIjSZ6olbEoT0u17Rag8BxnxryMrgR dkccq272MaSS0eOC9K2rtvxzddohRFPcy/8bkX+t2iukTDz75KSTKO+chce62Xxdg62dpkZX xK+HeDCZ7gRNZvAbDETr6XI63hPKi891GeZqvqQVYR8e+V2725w+H1iv3THiB1tx4L2bXZDI DtMKQ5D2RvCHNdPNcZeldEoJwKoA60yg6tuUquvsLvfCwtrmVI2rL2djYxRfGNmFMrUDN1Xq F3xozA91q3iZd9OYi9G+M/OA01husBdcIzj1hu0aL+MGg4Gqk6XwjoSxVd4YT41kTU7Kk+/I 5/Nf+i88ULt6HanBYcY/+Daeo/XFABEBAAGJAjYEGAEIACAWIQT7om49ONNvHjv2jc5a3lvU aWv7pQUCWYoE5AIbDAAKCRBa3lvUaWv7pfmcEACKTRQ28b1y5ztKuLdLr79+T+LwZKHjX++P 4wKjEOECCcB6KCv3hP+J2GCXDOPZvdg/ZYZafqP68Yy8AZqkfa4qPYHmIdpODtRzZSL48kM8 LRzV8Rl7J3ItvzdBRxf4T/Zseu5U6ELiQdCUkPGsJcPIJkgPjO2ROG/ZtYa9DvnShNWPlp+R uPwPccEQPWO/NP4fJl2zwC6byjljZhW5kxYswGMLBwb5cDUZAisIukyAa8Xshdan6C2RZcNs rB3L7vsg/R8UCehxOH0C+NypG2GqjVejNZsc7bgV49EOVltS+GmGyY+moIzxsuLmT93rqyII 5rSbbcTLe6KBYcs24XEoo49Zm9oDA3jYvNpeYD8rDcnNbuZh9kTgBwFN41JHOPv0W2FEEWqe JsCwQdcOQ56rtezdCJUYmRAt3BsfjN3Jn3N6rpodi4Dkdli8HylM5iq4ooeb5VkQ7UZxbCWt UVMKkOCdFhutRmYp0mbv2e87IK4erwNHQRkHUkzbsuym8RVpAZbLzLPIYK/J3RTErL6Z99N2 m3J6pjwSJY/zNwuFPs9zGEnRO4g0BUbwGdbuvDzaq6/3OJLKohr5eLXNU3JkT+3HezydWm3W OPhauth7W0db74Qd49HXK0xe/aPrK+Cp+kU1HRactyNtF8jZQbhMCC8vMGukZtWaAwpjWiiH bA== Message-ID: Date: Sun, 20 Dec 2020 19:15:05 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 20/12/2020 19:13, Pavel Begunkov wrote: > If io_ring_ctx_wait_and_kill() haven't killed all requests on the first > attempt, new timeouts or requests enqueued for polling may appear. They > won't be ever cancelled by io_ring_exit_work() unless we specifically > handle that case. That hangs of the exit work locking up grabbed by > io_uring resources. Josef and Dmitry, it would be great to have your Tested-by: <> > Cc: # 5.5+ > Cc: Josef > Reported-by: Dmitry Kadashev > Signed-off-by: Pavel Begunkov > --- > fs/io_uring.c | 55 +++++++++++++++++++++++++++------------------------ > 1 file changed, 29 insertions(+), 26 deletions(-) > > diff --git a/fs/io_uring.c b/fs/io_uring.c > index fbf747803dbc..c1acc668fe96 100644 > --- a/fs/io_uring.c > +++ b/fs/io_uring.c > @@ -8620,6 +8620,32 @@ static int io_remove_personalities(int id, void *p, void *data) > return 0; > } > > +static void io_cancel_defer_files(struct io_ring_ctx *ctx, > + struct task_struct *task, > + struct files_struct *files) > +{ > + struct io_defer_entry *de = NULL; > + LIST_HEAD(list); > + > + spin_lock_irq(&ctx->completion_lock); > + list_for_each_entry_reverse(de, &ctx->defer_list, list) { > + if (io_match_task(de->req, task, files)) { > + list_cut_position(&list, &ctx->defer_list, &de->list); > + break; > + } > + } > + spin_unlock_irq(&ctx->completion_lock); > + > + while (!list_empty(&list)) { > + de = list_first_entry(&list, struct io_defer_entry, list); > + list_del_init(&de->list); > + req_set_fail_links(de->req); > + io_put_req(de->req); > + io_req_complete(de->req, -ECANCELED); > + kfree(de); > + } > +} > + > static void io_ring_exit_work(struct work_struct *work) > { > struct io_ring_ctx *ctx = container_of(work, struct io_ring_ctx, > @@ -8633,6 +8659,8 @@ static void io_ring_exit_work(struct work_struct *work) > */ > do { > io_iopoll_try_reap_events(ctx); > + io_poll_remove_all(ctx, NULL, NULL); > + io_kill_timeouts(ctx, NULL, NULL); > } while (!wait_for_completion_timeout(&ctx->ref_comp, HZ/20)); > io_ring_ctx_free(ctx); > } > @@ -8654,6 +8682,7 @@ 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); > > + io_cancel_defer_files(ctx, NULL, NULL); > io_kill_timeouts(ctx, NULL, NULL); > io_poll_remove_all(ctx, NULL, NULL); > > @@ -8716,32 +8745,6 @@ static bool io_cancel_task_cb(struct io_wq_work *work, void *data) > return ret; > } > > -static void io_cancel_defer_files(struct io_ring_ctx *ctx, > - struct task_struct *task, > - struct files_struct *files) > -{ > - struct io_defer_entry *de = NULL; > - LIST_HEAD(list); > - > - spin_lock_irq(&ctx->completion_lock); > - list_for_each_entry_reverse(de, &ctx->defer_list, list) { > - if (io_match_task(de->req, task, files)) { > - list_cut_position(&list, &ctx->defer_list, &de->list); > - break; > - } > - } > - spin_unlock_irq(&ctx->completion_lock); > - > - while (!list_empty(&list)) { > - de = list_first_entry(&list, struct io_defer_entry, list); > - list_del_init(&de->list); > - req_set_fail_links(de->req); > - io_put_req(de->req); > - io_req_complete(de->req, -ECANCELED); > - kfree(de); > - } > -} > - > static void io_uring_cancel_files(struct io_ring_ctx *ctx, > struct task_struct *task, > struct files_struct *files) > -- Pavel Begunkov