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 6A38EC433F5 for ; Sun, 20 Feb 2022 04:38:34 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234106AbiBTEiv (ORCPT ); Sat, 19 Feb 2022 23:38:51 -0500 Received: from mxb-00190b01.gslb.pphosted.com ([23.128.96.19]:33700 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229727AbiBTEit (ORCPT ); Sat, 19 Feb 2022 23:38:49 -0500 Received: from mail-pj1-x102c.google.com (mail-pj1-x102c.google.com [IPv6:2607:f8b0:4864:20::102c]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id E6EB037BEE for ; Sat, 19 Feb 2022 20:38:28 -0800 (PST) Received: by mail-pj1-x102c.google.com with SMTP id q11-20020a17090a304b00b001b94d25eaecso12192282pjl.4 for ; Sat, 19 Feb 2022 20:38:28 -0800 (PST) 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 :cc:references:from:in-reply-to:content-transfer-encoding; bh=rarLEeWl7Jkzp0L5XhsI/l0oWNo+x0Oo6ZRlLhAli98=; b=G+XAmvW7rWg3IDRbr77eU/EpbCKWve+wFVhQeOMiLasFu+J9wt4XNMXmxHt8mif4OA 7Ek6rHVPPTmvQ/1rAU6UTZQzHBJbSlQ/Bqi1/bOPJMNSjNbKYdXdNDBq0bLabc1MwtUk uIGirQNSuS6XRTNjZPZUMjw3evXQ+PbiOZwm7PbjdSfUzKtOCCGMDB2wGAmSVHaAWbuB d4sMEXutZlpRvqa9WQd/UiPqXGmazcbvOGL6ng1GrJAbLPsaMzDcgzVs6uZYdhTbNQ3E nM3ZU4hA3Z9KNfD4XyafklCN+fVy85hIw5zJ7A6e2eA8qJj5gDCO0N7jMkIhuRBxixWM SH9w== 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:cc:references:from:in-reply-to :content-transfer-encoding; bh=rarLEeWl7Jkzp0L5XhsI/l0oWNo+x0Oo6ZRlLhAli98=; b=62lo/a7g/8i+I80Qov9873dLEkmuddjECSHQOckNx96y7h07jXBLKDLSnD4qBMapZK 9Ql8wlyKVXYr6F4d+hz1uEi7faVJ22nkSiWad08yxNLumtEPikWiqvmMcQ4RGAugAUyg pWaO14iCaHwhRxg6lYJZem/vIuL823HGI05AIu6Q0zC1vThOTrnmm9vqaIcjSQflW6LQ 3EJW1zAwNd3p17+zKmrcFQ1Zsrav7W8HH/0FgKsTaH5JIfA+ufoZqvHPzalbKaL1FfMk BUHEcqkPgYJSdkQfdFqihGQevTT4ZkQdP6IMJSziMaAttr1EaweWUZaKKjkcCl5Yi6hX sVGQ== X-Gm-Message-State: AOAM531+uRRgeZDx1kOkLt+sgeoMZU23vHTGdT8DeP4ORGx1knPbKLuC EO5Z6UPb9Jw4QEJI1UlHgv1EVw== X-Google-Smtp-Source: ABdhPJygf81+/wTX7gIEiPky2GmcZv4lalJOOWE6ow+ArFj4YwChbKqz+Cq5frhGuT0O1l4v9JL6hQ== X-Received: by 2002:a17:90a:5794:b0:1b9:8932:d475 with SMTP id g20-20020a17090a579400b001b98932d475mr15462773pji.24.1645331908402; Sat, 19 Feb 2022 20:38:28 -0800 (PST) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id b16sm8114248pfv.192.2022.02.19.20.38.26 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Sat, 19 Feb 2022 20:38:27 -0800 (PST) Message-ID: <7b2b2a34-601a-e62e-3e89-e19954dc965c@kernel.dk> Date: Sat, 19 Feb 2022 21:38:26 -0700 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.6.0 Subject: Re: [PATCH v2 04/13] fs: split off __alloc_page_buffers function Content-Language: en-US To: Matthew Wilcox , Christoph Hellwig Cc: Stefan Roesch , io-uring@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, kernel-team@fb.com References: <20220218195739.585044-1-shr@fb.com> <20220218195739.585044-5-shr@fb.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-block@vger.kernel.org On 2/19/22 9:23 PM, Matthew Wilcox wrote: > On Fri, Feb 18, 2022 at 11:35:10PM -0800, Christoph Hellwig wrote: >> Err, hell no. Please do not add any new functionality to the legacy >> buffer head code. If you want new features do that on the >> non-bufferhead iomap code path only please. > > I think "first convert the block device code from buffer_heads to > iomap" might be a bit much of a prerequisite. I think running ext4 on > top of a Yes, that's exactly what Christoph was trying to say, but failing to state in an appropriate manner. And we did actually discuss that, I'm not against doing something like that. > block device still requires buffer_heads, for example (I tried to convert > the block device to use mpage in order to avoid creating buffer_heads > when possible, and ext4 stopped working. I didn't try too hard to debug > it as it was a bit of a distraction at the time). That's one of the main reasons why I didn't push this particular path, as it is a bit fraught with weirdness and legacy buffer_head code which isn't that easy to tackle... -- Jens Axboe