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 F379CC4167B for ; Fri, 4 Dec 2020 11:48:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CE26422A99 for ; Fri, 4 Dec 2020 11:48:16 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730016AbgLDLsI (ORCPT ); Fri, 4 Dec 2020 06:48:08 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40666 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728300AbgLDLsI (ORCPT ); Fri, 4 Dec 2020 06:48:08 -0500 Received: from mail-wr1-x443.google.com (mail-wr1-x443.google.com [IPv6:2a00:1450:4864:20::443]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id DFB9EC0613D1; Fri, 4 Dec 2020 03:47:27 -0800 (PST) Received: by mail-wr1-x443.google.com with SMTP id g14so4999505wrm.13; Fri, 04 Dec 2020 03:47:27 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=to:cc:references:from:autocrypt:subject:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=UclILjREAUdtSCUnNunr1tBo79Qe+ptgrQIOw+TFsoM=; b=IZJp/928EbYWlLCdaAxmvn43bZP4sYw40tYOrIOI3CdMqabuLncFThj9ZskC2xlqTw /h93HBKSWW7KGlwkf6DYp2F2ykACszeUDxs3PKy2AvcoZGJZHddxeEhDjWUlSKs1wski fvNf/3c8IkhFUjNZHYQ9rRNC7+PaySvoNusa5+LfGsc7Lyxd3oL6vXRnirHJUmGwAh+6 3mMnqm7NRHbI39/5+z+sfO9dYuqQsPf/gV3mDCaOR/jo/iVdVkZaASOtTITixwFTNVpP qyFGNTL2qQIRHtRyxOEHDYYBs2IyKN7oFBbEmJdwBfdEAXCNi5agy1lMaIoJLr4o+JOX oY6w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:to:cc:references:from:autocrypt:subject :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=UclILjREAUdtSCUnNunr1tBo79Qe+ptgrQIOw+TFsoM=; b=kW+szsF0qfBE7TB9mlicZV4OLn4epWFXdeW0dRA+X2sbsAdTxmEg6qtZ1BOcD5DBqy Ik5kFHmPwld0l/6ww5I7B/UfpuTbni4mZBDkG5IFznmEcKj2d6xNbtBl55/XG8DTRi1W /JFY/xFqRzEsQWNPO6wYPkIBNh6xJIWNjcNKxM99u9GeFdXC/goxRipL/NAxqiWB0SxM VQgmB5Pw+c1j3PA+4Gjc/lTeYs825s/r7xJpYpUaKwhp/v62ZuUAJQvZFmpGuhnQJhTM IcAJddTYJXEEeuVeDet/FEojNbIqijvrOOESrdX2eaQxK5RrmJMd9BTu0tzfYm0L/qEl LrCg== X-Gm-Message-State: AOAM532e3jg2KpnszCiYndnpnJ5XWfFPBiBkaKKJGOV2c3wfqBwqbFa1 SF6hrz4HrqmwZMPpJjH/etvZ+cLqKNZUreI/ X-Google-Smtp-Source: ABdhPJw+zzAIT76+0aIQMwoRW4rYVeC9sXvMQvmUnFTeVJ7Z6HxCwbu3zAQSqY3c9tPaFvyRoRFv1w== X-Received: by 2002:a5d:5146:: with SMTP id u6mr4762003wrt.66.1607082446373; Fri, 04 Dec 2020 03:47:26 -0800 (PST) Received: from [192.168.1.118] (host109-152-100-189.range109-152.btcentralplus.com. [109.152.100.189]) by smtp.gmail.com with ESMTPSA id h20sm2742058wmb.29.2020.12.04.03.47.24 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 04 Dec 2020 03:47:25 -0800 (PST) To: Hao Xu , Alexander Viro , Christoph Hellwig Cc: "Darrick J. Wong" , linux-fsdevel@vger.kernel.org, Jeffle Xu , Konstantin Khlebnikov , Jens Axboe , io-uring@vger.kernel.org, Joseph Qi , linux-block@vger.kernel.org References: <1607075096-94235-1-git-send-email-haoxu@linux.alibaba.com> 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== Subject: Re: [PATCH v3 RESEND] iomap: set REQ_NOWAIT according to IOCB_NOWAIT in Direct IO Message-ID: Date: Fri, 4 Dec 2020 11:44:10 +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: <1607075096-94235-1-git-send-email-haoxu@linux.alibaba.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: io-uring@vger.kernel.org On 04/12/2020 09:44, Hao Xu wrote: > Currently, IOCB_NOWAIT is ignored in Direct IO, REQ_NOWAIT is only set > when IOCB_HIPRI is set. But REQ_NOWAIT should be set as well when > IOCB_NOWAIT is set. I believe Jens took my patch fixing that for blkdev_direct_IO*() (but not iomap) a while ago. BTW, even though get_maintainer.pl doesn't think so, AFAIK fs/block_dev.c is managed by linux-block@vger.kernel.org. Please CC it next time. > Suggested-by: Jeffle Xu > Signed-off-by: Konstantin Khlebnikov > Signed-off-by: Hao Xu > --- > > Hi all, > I tested fio io_uring direct read for a file on ext4 filesystem on a > nvme ssd. I found that IOCB_NOWAIT is ignored in iomap layer, which > means REQ_NOWAIT is not set in bio->bi_opf. This makes nowait IO a > normal IO. Since I'm new to iomap and block layer, I sincerely ask > yours opinions in case I misunderstand the code which is very likely > to happen.:) > The example I use: io_uring direct randread, the first try is with > IOCB_NOWAIT but not IOCB_HIPRI, the IOCB_NOWAIT is ignored in block > layer which I think is not the designed behaviour. > > I found that Konstantin found this issue before in May > 2020 (https://www.spinics.net/lists/linux-block/msg53275.html), here add > his signature, add Jeffle's as well since he gave me some help. > > v1->v2: > * add same logic in __blkdev_direct_IO_simple() > v2->v3: > * add same logic in do_blockdev_direct_IO() > > fs/block_dev.c | 7 +++++++ > fs/direct-io.c | 6 ++++-- > fs/iomap/direct-io.c | 3 +++ > 3 files changed, 14 insertions(+), 2 deletions(-) > > diff --git a/fs/block_dev.c b/fs/block_dev.c > index 9e84b1928b94..ca6f365c2f14 100644 > --- a/fs/block_dev.c > +++ b/fs/block_dev.c > @@ -263,6 +263,10 @@ static void blkdev_bio_end_io_simple(struct bio *bio) > bio.bi_opf = dio_bio_write_op(iocb); > task_io_account_write(ret); > } > + > + if (iocb->ki_flags & IOCB_NOWAIT) > + bio.bi_opf |= REQ_NOWAIT; > + > if (iocb->ki_flags & IOCB_HIPRI) > bio_set_polled(&bio, iocb); > > @@ -417,6 +421,9 @@ static void blkdev_bio_end_io(struct bio *bio) > task_io_account_write(bio->bi_iter.bi_size); > } > > + if (iocb->ki_flags & IOCB_NOWAIT) > + bio->bi_opf |= REQ_NOWAIT; > + > dio->size += bio->bi_iter.bi_size; > pos += bio->bi_iter.bi_size; > > diff --git a/fs/direct-io.c b/fs/direct-io.c > index d53fa92a1ab6..b221ed351c1c 100644 > --- a/fs/direct-io.c > +++ b/fs/direct-io.c > @@ -1206,11 +1206,13 @@ static inline int drop_refcount(struct dio *dio) > if (iov_iter_rw(iter) == WRITE) { > dio->op = REQ_OP_WRITE; > dio->op_flags = REQ_SYNC | REQ_IDLE; > - if (iocb->ki_flags & IOCB_NOWAIT) > - dio->op_flags |= REQ_NOWAIT; > } else { > dio->op = REQ_OP_READ; > } > + > + if (iocb->ki_flags & IOCB_NOWAIT) > + dio->op_flags |= REQ_NOWAIT; > + > if (iocb->ki_flags & IOCB_HIPRI) > dio->op_flags |= REQ_HIPRI; > > diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c > index 933f234d5bec..2e897688ed6d 100644 > --- a/fs/iomap/direct-io.c > +++ b/fs/iomap/direct-io.c > @@ -64,6 +64,9 @@ static void iomap_dio_submit_bio(struct iomap_dio *dio, struct iomap *iomap, > { > atomic_inc(&dio->ref); > > + if (dio->iocb->ki_flags & IOCB_NOWAIT) > + bio->bi_opf |= REQ_NOWAIT; > + > if (dio->iocb->ki_flags & IOCB_HIPRI) > bio_set_polled(bio, dio->iocb); > > -- Pavel Begunkov