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=-6.8 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS 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 176C6C433E1 for ; Mon, 24 Aug 2020 21:09:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E90FA2072D for ; Mon, 24 Aug 2020 21:09:17 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=osandov-com.20150623.gappssmtp.com header.i=@osandov-com.20150623.gappssmtp.com header.b="zTHfp5qr" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726365AbgHXVJO (ORCPT ); Mon, 24 Aug 2020 17:09:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39886 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726241AbgHXVJN (ORCPT ); Mon, 24 Aug 2020 17:09:13 -0400 Received: from mail-pg1-x544.google.com (mail-pg1-x544.google.com [IPv6:2607:f8b0:4864:20::544]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 6AF58C0613ED for ; Mon, 24 Aug 2020 14:09:13 -0700 (PDT) Received: by mail-pg1-x544.google.com with SMTP id 67so2137508pgd.12 for ; Mon, 24 Aug 2020 14:09:13 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=osandov-com.20150623.gappssmtp.com; s=20150623; h=date:from:to:cc:subject:message-id:references:mime-version :content-disposition:in-reply-to; bh=7mXzq4VFpfuTDMAhROUx/v2Tiks/oGuPIrAnlV7pgL4=; b=zTHfp5qr9CXMgLDiKCc7NSmUQwK6QjM2JRLdQcH/DW7bFmEVhszUdGCy9Vil82o0c2 8yrnc6o7DnNlnvV49BeADtWAycT76MkV3D96tx3jqQi51qoxIosCT3a2NMgtcoId7+fM da8TR20fUZslEmqDKgIlbRZLf49p2cUEAIiRvModUkvSYMG0MmAxAEhh7KZE+uAFBjo5 4rBX0rtPmzRQxV3uo86JpUHRkkufs3g+MwpOiNhJMUI7CLB0CXD8vPGOAQ7pSTcCvuyS BFyZm4Log32Szpc+5RJVCbTso/pMTlpbwHFCs8MaqXlSRIdH7q+9LI7cFIpJpl11HfpY /qqg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:date:from:to:cc:subject:message-id:references :mime-version:content-disposition:in-reply-to; bh=7mXzq4VFpfuTDMAhROUx/v2Tiks/oGuPIrAnlV7pgL4=; b=sFvMWeiKzRZ/RwQfpNIUine89XNrLhvclr8OK7x3LvaEGLkzxwi1hFIhPs33h7xrtb jiBjHitMfpzIPxFcHPXdIKj/OQh5pK+80vlc/NRwk7nyRl0cbXIo2u7S5A6M8unuT6tz bvtU1meavuvG/u+y/9zkWt/Q7XLW3DlsKsZi8fwQEgI0p1qzhm1vLhP9sMaBaMqdWNdr 9QVDwqMg1Mop3wl0zSsyo2mH/d0B6EZdBWq3KNonlf9dUwIiwGX4gTSfE61H0Nvyswgy JaM8bnq6AEdf9Ufj5zbsbECIpewJZhfhCp5bgQFKRUhI2CzfMqRah+T3PjhUDTwTkH4Z cTTg== X-Gm-Message-State: AOAM533DyxUEuM2VkZ6nRyryUBrQbAqJASVU2jVxbTTljfKreuK8hGYF 2IMVJccYbm8341K1Jw9lrt1JLQ== X-Google-Smtp-Source: ABdhPJzBAcC6lTewhNgiycLtkJLMlcv1GmqUho/7ezq+g/7n5HwmWJRm1mNtwP4WW1HLG2qQ1hlzKg== X-Received: by 2002:a63:e703:: with SMTP id b3mr4510239pgi.39.1598303352545; Mon, 24 Aug 2020 14:09:12 -0700 (PDT) Received: from exodia.localdomain ([2620:10d:c090:400::5:8d5d]) by smtp.gmail.com with ESMTPSA id 13sm12677300pfp.3.2020.08.24.14.09.10 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Mon, 24 Aug 2020 14:09:11 -0700 (PDT) Date: Mon, 24 Aug 2020 14:09:09 -0700 From: Omar Sandoval To: Josef Bacik Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, Al Viro , Christoph Hellwig , Dave Chinner , Jann Horn , Amir Goldstein , Aleksa Sarai , linux-api@vger.kernel.org, kernel-team@fb.com Subject: Re: [PATCH v5 1/9] iov_iter: add copy_struct_from_iter() Message-ID: <20200824210909.GA197795@exodia.localdomain> References: <8010f8862ec494c631b1d7681a6c5886d12f60df.1597993855.git.osandov@osandov.com> <93eca2d1-f72c-2181-b6a4-7015886f2418@toxicpanda.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <93eca2d1-f72c-2181-b6a4-7015886f2418@toxicpanda.com> Sender: linux-api-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-api@vger.kernel.org On Mon, Aug 24, 2020 at 02:52:24PM -0400, Josef Bacik wrote: > On 8/21/20 3:38 AM, Omar Sandoval wrote: > > From: Omar Sandoval > > > > This is essentially copy_struct_from_user() but for an iov_iter. > > > > Suggested-by: Aleksa Sarai > > Signed-off-by: Omar Sandoval > > This took me a lot longer to grok than I'm proud of, but the idea is you'll > have a single segment that represents the incoming encoded data, and then > subsequent segments will be the read/write buffer, correct? The code looks > fine to me, > > Reviewed-by: Josef Bacik > > Thanks, > > Josef Yes, that's the idea for RWF_ENCODED. This patch is the generic way to shove an extra metadata struct at the beginning of an iov_iter in a way that is backwards/forwards compatible. Thanks!