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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 autolearn=no 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 00A7DC2D0EC for ; Sat, 28 Mar 2020 18:39:54 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id D685B2076E for ; Sat, 28 Mar 2020 18:39:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726325AbgC1Sjx (ORCPT ); Sat, 28 Mar 2020 14:39:53 -0400 Received: from mail-pj1-f67.google.com ([209.85.216.67]:37347 "EHLO mail-pj1-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726220AbgC1Sjw (ORCPT ); Sat, 28 Mar 2020 14:39:52 -0400 Received: by mail-pj1-f67.google.com with SMTP id o12so5311624pjs.2; Sat, 28 Mar 2020 11:39:51 -0700 (PDT) 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=XerZ3Gorggp6JfGE9WxhW/P41bOToikN7aDIdEAHasU=; b=Fgi4zVB+S6Cs2sFQrf5/FkaaH2k2EpnLgL4hyzJK825ASyIblcL03S8wATdRC0CBmk r+QCrRLOEqrxwvPAtdHmxPNS4bW75VC+AuhFycmewDAG32wLqdp2vfMejj2q+14ptkP+ hOG1GVNPLDbYc1xbpYiApcPPrdj6UnOLir77sMEWog3QvBPCMi4JW57/d5hj+cu0FYmF Nef0Q4KmrS5hFRLNw9126VX5glK9wLuAN5eURyBiJTaWBtkMnhshZFW9eGgsDxK4Y3fv pAdsB2HJwBpJPOQRfpW6MrJ9SVZ+d4S2I/+3y7wvTLTZMVHsaY4F43XPB8+6NAR0eMN4 ElhA== X-Gm-Message-State: ANhLgQ1rBvWbFipSzJ6Vk2SykX2WQu14Ts4avsgG0ejzGcuieAlpiOIg TIT5hKjcFAw1NL4YUPkcF0E= X-Google-Smtp-Source: ADFU+vsYYKjO2+LiH7X1NsG9tMzGqwyerZnbgfYC0fuyGOSYCllpNPIdjpiLvHCBdUAzbn/j4tW/Jg== X-Received: by 2002:a17:90a:37c6:: with SMTP id v64mr6441101pjb.20.1585420791214; Sat, 28 Mar 2020 11:39:51 -0700 (PDT) Received: from ?IPv6:2601:647:4000:d7:597d:a863:13de:4665? ([2601:647:4000:d7:597d:a863:13de:4665]) by smtp.gmail.com with ESMTPSA id k20sm6216119pgn.62.2020.03.28.11.39.49 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 28 Mar 2020 11:39:50 -0700 (PDT) Subject: Re: [PATCH v11 22/26] block/rnbd: server: functionality for IO submission to file or block dev To: Jack Wang , linux-block@vger.kernel.org, linux-rdma@vger.kernel.org Cc: axboe@kernel.dk, hch@infradead.org, sagi@grimberg.me, leon@kernel.org, dledford@redhat.com, jgg@ziepe.ca, danil.kipnis@cloud.ionos.com, rpenyaev@suse.de, pankaj.gupta@cloud.ionos.com References: <20200320121657.1165-1-jinpu.wang@cloud.ionos.com> <20200320121657.1165-23-jinpu.wang@cloud.ionos.com> From: Bart Van Assche Autocrypt: addr=bvanassche@acm.org; prefer-encrypt=mutual; keydata= mQENBFSOu4oBCADcRWxVUvkkvRmmwTwIjIJvZOu6wNm+dz5AF4z0FHW2KNZL3oheO3P8UZWr LQOrCfRcK8e/sIs2Y2D3Lg/SL7qqbMehGEYcJptu6mKkywBfoYbtBkVoJ/jQsi2H0vBiiCOy fmxMHIPcYxaJdXxrOG2UO4B60Y/BzE6OrPDT44w4cZA9DH5xialliWU447Bts8TJNa3lZKS1 AvW1ZklbvJfAJJAwzDih35LxU2fcWbmhPa7EO2DCv/LM1B10GBB/oQB5kvlq4aA2PSIWkqz4 3SI5kCPSsygD6wKnbRsvNn2mIACva6VHdm62A7xel5dJRfpQjXj2snd1F/YNoNc66UUTABEB AAG0JEJhcnQgVmFuIEFzc2NoZSA8YnZhbmFzc2NoZUBhY20ub3JnPokBOQQTAQIAIwUCVI67 igIbAwcLCQgHAwIBBhUIAgkKCwQWAgMBAh4BAheAAAoJEHFcPTXFzhAJ8QkH/1AdXblKL65M Y1Zk1bYKnkAb4a98LxCPm/pJBilvci6boefwlBDZ2NZuuYWYgyrehMB5H+q+Kq4P0IBbTqTa jTPAANn62A6jwJ0FnCn6YaM9TZQjM1F7LoDX3v+oAkaoXuq0dQ4hnxQNu792bi6QyVdZUvKc macVFVgfK9n04mL7RzjO3f+X4midKt/s+G+IPr4DGlrq+WH27eDbpUR3aYRk8EgbgGKvQFdD CEBFJi+5ZKOArmJVBSk21RHDpqyz6Vit3rjep7c1SN8s7NhVi9cjkKmMDM7KYhXkWc10lKx2 RTkFI30rkDm4U+JpdAd2+tP3tjGf9AyGGinpzE2XY1K5AQ0EVI67igEIAKiSyd0nECrgz+H5 PcFDGYQpGDMTl8MOPCKw/F3diXPuj2eql4xSbAdbUCJzk2ETif5s3twT2ER8cUTEVOaCEUY3 eOiaFgQ+nGLx4BXqqGewikPJCe+UBjFnH1m2/IFn4T9jPZkV8xlkKmDUqMK5EV9n3eQLkn5g lco+FepTtmbkSCCjd91EfThVbNYpVQ5ZjdBCXN66CKyJDMJ85HVr5rmXG/nqriTh6cv1l1Js T7AFvvPjUPknS6d+BETMhTkbGzoyS+sywEsQAgA+BMCxBH4LvUmHYhpS+W6CiZ3ZMxjO8Hgc ++w1mLeRUvda3i4/U8wDT3SWuHcB3DWlcppECLkAEQEAAYkBHwQYAQIACQUCVI67igIbDAAK CRBxXD01xc4QCZ4dB/0QrnEasxjM0PGeXK5hcZMT9Eo998alUfn5XU0RQDYdwp6/kMEXMdmT oH0F0xB3SQ8WVSXA9rrc4EBvZruWQ+5/zjVrhhfUAx12CzL4oQ9Ro2k45daYaonKTANYG22y //x8dLe2Fv1By4SKGhmzwH87uXxbTJAUxiWIi1np0z3/RDnoVyfmfbbL1DY7zf2hYXLLzsJR mSsED/1nlJ9Oq5fALdNEPgDyPUerqHxcmIub+pF0AzJoYHK5punqpqfGmqPbjxrJLPJfHVKy goMj5DlBMoYqEgpbwdUYkH6QdizJJCur4icy8GUNbisFYABeoJ91pnD4IGei3MTdvINSZI5e Message-ID: Date: Sat, 28 Mar 2020 11:39:49 -0700 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.6.0 MIME-Version: 1.0 In-Reply-To: <20200320121657.1165-23-jinpu.wang@cloud.ionos.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-block-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-block@vger.kernel.org On 2020-03-20 05:16, Jack Wang wrote: > This provides helper functions for IO submission to file or block dev. Regarding the title of this patch: is file I/O still supported? Wasn't that support removed some time ago? > +struct rnbd_dev *rnbd_dev_open(const char *path, fmode_t flags, > + void (*io_cb)(void *priv, int error)) > +{ > + struct rnbd_dev *dev; > + int ret; > + > + dev = kzalloc(sizeof(*dev), GFP_KERNEL); > + if (!dev) > + return ERR_PTR(-ENOMEM); > + > + dev->blk_open_flags = flags; > + dev->bdev = blkdev_get_by_path(path, flags, THIS_MODULE); > + ret = PTR_ERR_OR_ZERO(dev->bdev); > + if (ret) > + goto err; > + > + dev->blk_open_flags = flags; > + dev->io_cb = io_cb; > + bdevname(dev->bdev, dev->name); > + > + return dev; > + > +err: > + kfree(dev); > + return ERR_PTR(ret); > +} This function only has one caller so io_cb is always equal to the argument passed by that single caller, namely rnbd_endio. If that argument and also dev->io_cb would be removed, would that make the hot path faster? > +int rnbd_dev_submit_io(struct rnbd_dev *dev, sector_t sector, void *data, > + size_t len, u32 bi_size, enum rnbd_io_flags flags, > + short prio, void *priv) > +{ > + struct request_queue *q = bdev_get_queue(dev->bdev); > + struct rnbd_dev_blk_io *io; > + struct bio *bio; > + > + /* check if the buffer is suitable for bdev */ > + if (WARN_ON(!blk_rq_aligned(q, (unsigned long)data, len))) > + return -EINVAL; The blk_rq_aligned() check looks weird to me. bio_map_kern() can handle data buffers that do not match the DMA alignment requirements, so why to refuse data buffers that are not satisfy DMA alignment requirements? > + /* Generate bio with pages pointing to the rdma buffer */ > + bio = bio_map_kern(q, data, len, GFP_KERNEL); > + if (IS_ERR(bio)) > + return PTR_ERR(bio); > + > + io = kmalloc(sizeof(*io), GFP_KERNEL); > + if (unlikely(!io)) { > + bio_put(bio); > + return -ENOMEM; > + } > + > + io->dev = dev; > + io->priv = priv; > + > + bio->bi_end_io = rnbd_dev_bi_end_io; > + bio->bi_private = io; > + bio->bi_opf = rnbd_to_bio_flags(flags); > + bio->bi_iter.bi_sector = sector; > + bio->bi_iter.bi_size = bi_size; > + bio_set_prio(bio, prio); > + bio_set_dev(bio, dev->bdev); I think Jason strongly prefers to have a single space at the left of the assignment operator. Thanks, Bart.