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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 55B19C433F5 for ; Fri, 20 May 2022 14:36:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1349965AbiETOgZ (ORCPT ); Fri, 20 May 2022 10:36:25 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:53370 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233904AbiETOgV (ORCPT ); Fri, 20 May 2022 10:36:21 -0400 Received: from mail-pl1-x635.google.com (mail-pl1-x635.google.com [IPv6:2607:f8b0:4864:20::635]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 27AAF56779 for ; Fri, 20 May 2022 07:36:20 -0700 (PDT) Received: by mail-pl1-x635.google.com with SMTP id i1so7523488plg.7 for ; Fri, 20 May 2022 07:36:20 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language:to :references:from:in-reply-to:content-transfer-encoding; bh=INFqOgoNC8M2kVfmoFeOv9h9ykovwpCyeybqDjrCvqM=; b=w03MvGAGC+lICJ+stSchnIesIheHXMiHhf0qrEVv67QbymHRXNbIypjXQ+EqeUnBuy 6D4IttDBhpA9QAUnxhpVtgMsyMJGNe7NbVv6HSKeO+XC8WdgE7dBa+epExGgye/AIa8B csMprCAqlxRNdOB0B/WQF6ty1+oRuVpsspYWwo0OmVUGfQbVBzg+W0WFjaSr8leQBWhV Reb0jwJpnoBujnOIQgBFBvzScsg0CmrMOg0kw2ZyiSe1VGOAskAqE6ZlA0jdYnHyvk4v tgJaokan8D56Ge9H+B6Sqc1hoqJ/yB4vvlj4F8V5pUL72lvJ8aa4D3uV/3IS+X0FFhLZ WZ9w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:to:references:from:in-reply-to :content-transfer-encoding; bh=INFqOgoNC8M2kVfmoFeOv9h9ykovwpCyeybqDjrCvqM=; b=2DfwboCzsTL0oxGqZ/TxQrgTjzno2nvZhHhzI/I80cNy9I0QA3OsedCDA2PJwasZWF ZsmLSFCp7kGu5TAcakOt6Z2oEgh8qhjnX446mdtQndAigBj/AFxb56uSXF/YR8Rd4ThI gskqk6dc3gqMxI13hVy4fzO6yo8tltZnK/OjIKNWhX7EaE4TREG0v7f/zhy9xT1XeZCQ 69esuUgyFrnjd7FhNtg4oezuTDEmdIGkqcBSszQ2hhg0ubpMdU5Si11sFtJCoPtn2mU0 1xizVdJCuE0hUz0y7pxtbq6r3qBDkp+QlaqZx3lcW/0ofVLOcGwrRkl1RavOshlgG6kJ Og6A== X-Gm-Message-State: AOAM533U533NsH2qxJkJZYzo49cLWUOA2Swbhx1RbWjI3Ne9cRQEcrXZ mHV2JxCD1CFmsWRGDl5By5Hd0M9WjkbDhg== X-Google-Smtp-Source: ABdhPJzUkmKyY1r8SzhHanCj/XsjiifTUk1pF5AJAsg0szitt8lG3Soz6+x8pP6Zf2UXY6if4UWT/g== X-Received: by 2002:a17:90b:4f47:b0:1df:ef58:d055 with SMTP id pj7-20020a17090b4f4700b001dfef58d055mr6128568pjb.82.1653057379617; Fri, 20 May 2022 07:36:19 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id o9-20020a170902d4c900b0015e8d4eb1dfsm5787324plg.41.2022.05.20.07.36.18 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 20 May 2022 07:36:19 -0700 (PDT) Message-ID: <35a5ff9f-79d7-feb5-dfa7-a775b9352416@kernel.dk> Date: Fri, 20 May 2022 08:36:17 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.8.1 Subject: Re: [PATCH v4 1/3] random: convert to using fops->read_iter() Content-Language: en-US To: "Jason A. Donenfeld" , Theodore Ts'o , Christoph Hellwig , LKML , Al Viro References: <20220520094459.116240-1-Jason@zx2c4.com> <20220520094459.116240-2-Jason@zx2c4.com> From: Jens Axboe In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 5/20/22 7:37 AM, Jason A. Donenfeld wrote: > On Fri, May 20, 2022 at 11:44:57AM +0200, Jason A. Donenfeld wrote: >> const struct file_operations urandom_fops = { >> - .read = urandom_read, >> + .read_iter = urandom_read_iter, > > One thing I noticed is that drivers/char/mem.c has both the .read and > the .read_iter functions for /dev/zero and /dev/null and such. I wonder > if the .read ones can be removed? I'm not sure if we have a clear "always use this if available" set of rules for this. Ideally we'd want it to be: 1) Use ->read_iter() if available 2) If not, use ->read() Might require a bit of auditing to ensure that's the case, and if we can say that it is, then we could clean that up too. -- Jens Axboe