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=-14.3 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,URIBL_BLOCKED, 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 21B96C433E9 for ; Mon, 4 Jan 2021 16:11:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E5B66205CA for ; Mon, 4 Jan 2021 16:11:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729401AbhADQKz (ORCPT ); Mon, 4 Jan 2021 11:10:55 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:47392 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728650AbhADQKu (ORCPT ); Mon, 4 Jan 2021 11:10:50 -0500 Received: from mail-wm1-x32b.google.com (mail-wm1-x32b.google.com [IPv6:2a00:1450:4864:20::32b]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 4AFD6C061574; Mon, 4 Jan 2021 08:10:10 -0800 (PST) Received: by mail-wm1-x32b.google.com with SMTP id v14so18940085wml.1; Mon, 04 Jan 2021 08:10:10 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=XOhzcSd5DMVVTm4CdxSNXR0PEHTt4MMP6CDXjCJGwgo=; b=V0Qe5XNsDUL2b55pr7WGb++qC5Rj2qgPOmPpc77u2fRGs56JoWN4EU2xg7gzgG2+LW Ny7jMa0jt7uwyivwnfVIBeivTWF4o9J1b/k1Y1paJA2NCy7204BrWePrL/mI6/h/3zbl lL7FIXicR2T5AU+nc2a2CmCpVITq3YwCgIzvccm71HdRqOOHZiIGfVr+jK2dPsYeYhDm gBAbXR80S9IlgL3gM2LPX3l8Z1VGQsQio155N7R1n5GwNA1ey4ObUiF/a1MSIkluRPzi 4KYFrrE9z6/ferwLvbNKwPZEKWqV2C7gd3aKl0E3vlCmdcsFNibJK4Bpn8pCmrMDLPF1 DDkg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=XOhzcSd5DMVVTm4CdxSNXR0PEHTt4MMP6CDXjCJGwgo=; b=r1EtwP60xc0hLecX86pL7PnTFvbJC6ATjIokLAOoYD02KJ69vZMZrCu3l4EI2X4TcU mwXVumXI9utoedENHnRWuFTjFpNU9WcqDFVCz+S4sdebe4QdHxQSbNLobHTyrA2yDjIK qhpCzPsbEqRuyU7ihlLOhDR27gd5rw6UoVnGD7abEj6JWT1A3CxwAottd1UQgXcZz8kQ R9/m1x89LA0moTMfMoEmqXbTx8Jso0ASKb7AocgLwbGTmkDX2ThLFrJxZW5xQD0qvtHf 2SOHGakId9J1b5jBnpvoMIA78CiVYaaEC+Ab12/dakQqYXz9yA9BK+eYmKCJEuBDddlp TVlg== X-Gm-Message-State: AOAM531KQYrLgKIPBUww1y1qKwJkXuBu3qoVXqYDnJtkb/rsRYE5rAHF 6hfR08naE363auZpdWrKGLg= X-Google-Smtp-Source: ABdhPJwdDAREhvXRMBhZP25AhN4f445+u5q3aXFp+LSZEQYYYCl0M7UAYiKKRa/ltoHf5KmI94Xz9g== X-Received: by 2002:a1c:6484:: with SMTP id y126mr27322035wmb.76.1609776609041; Mon, 04 Jan 2021 08:10:09 -0800 (PST) Received: from [192.168.8.189] ([85.255.233.205]) by smtp.gmail.com with ESMTPSA id o13sm72131739wrh.88.2021.01.04.08.10.08 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Mon, 04 Jan 2021 08:10:08 -0800 (PST) Subject: Re: [PATCH 5.10 21/63] kernel/io_uring: cancel io_uring before task works To: Greg Kroah-Hartman , linux-kernel@vger.kernel.org Cc: stable@vger.kernel.org, Jens Axboe References: <20210104155708.800470590@linuxfoundation.org> <20210104155709.846535201@linuxfoundation.org> From: Pavel Begunkov 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: <2e03dac2-a91c-ede1-0109-a4d4297e3efd@gmail.com> Date: Mon, 4 Jan 2021 16:06:39 +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: <20210104155709.846535201@linuxfoundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 04/01/2021 15:57, Greg Kroah-Hartman wrote: > From: Pavel Begunkov > > commit b1b6b5a30dce872f500dc43f067cba8e7f86fc7d upstream. > > For cancelling io_uring requests it needs either to be able to run > currently enqueued task_works or having it shut down by that moment. > Otherwise io_uring_cancel_files() may be waiting for requests that won't > ever complete. Greg, can you drop it from stable for now? I'll backport it later when related problems are sorted. > > Go with the first way and do cancellations before setting PF_EXITING and > so before putting the task_work infrastructure into a transition state > where task_work_run() would better not be called. > > Cc: stable@vger.kernel.org # 5.5+ > Signed-off-by: Pavel Begunkov > Signed-off-by: Jens Axboe > Signed-off-by: Greg Kroah-Hartman > > --- > fs/file.c | 2 -- > kernel/exit.c | 2 ++ > 2 files changed, 2 insertions(+), 2 deletions(-) > > --- a/fs/file.c > +++ b/fs/file.c > @@ -21,7 +21,6 @@ > #include > #include > #include > -#include > > unsigned int sysctl_nr_open __read_mostly = 1024*1024; > unsigned int sysctl_nr_open_min = BITS_PER_LONG; > @@ -453,7 +452,6 @@ void exit_files(struct task_struct *tsk) > struct files_struct * files = tsk->files; > > if (files) { > - io_uring_files_cancel(files); > task_lock(tsk); > tsk->files = NULL; > task_unlock(tsk); > --- a/kernel/exit.c > +++ b/kernel/exit.c > @@ -63,6 +63,7 @@ > #include > #include > #include > +#include > > #include > #include > @@ -762,6 +763,7 @@ void __noreturn do_exit(long code) > schedule(); > } > > + io_uring_files_cancel(tsk->files); > exit_signals(tsk); /* sets PF_EXITING */ > > /* sync mm's RSS info before statistics gathering */ > > -- Pavel Begunkov