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=-7.3 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,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 E6113C433DB for ; Tue, 22 Dec 2020 19:40:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B892923137 for ; Tue, 22 Dec 2020 19:40:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726703AbgLVTkm (ORCPT ); Tue, 22 Dec 2020 14:40:42 -0500 Received: from us-smtp-delivery-124.mimecast.com ([216.205.24.124]:30751 "EHLO us-smtp-delivery-124.mimecast.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725902AbgLVTkm (ORCPT ); Tue, 22 Dec 2020 14:40:42 -0500 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1608665955; h=from:from:reply-to:subject:subject:date:date:message-id:message-id: to:to:cc:cc:mime-version:mime-version:content-type:content-type: in-reply-to:in-reply-to:references:references; bh=5tsCMd9Nfdq9n0ayDvsC2lk0uNSEwrw9mxvuZSf1qkQ=; b=cIt9xSgztQF42RsjQiBEtvGn9H2C9QcEByLQVXIPsH32b3wg8jjFUGC8087xcL95EeRzEs Jasu72grbDD7+3orD5anvbdDdUHTsxxfaB7NDWaCKCjVaPND+yF1V8ZpfqzkFQYQf2nyjU 49pM5ekSnKOjm8LZNkUYjb1csvoGFoc= Received: from mail-pf1-f200.google.com (mail-pf1-f200.google.com [209.85.210.200]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-265-yw9uQnqcOJaoVPnHOiD1DA-1; Tue, 22 Dec 2020 14:39:13 -0500 X-MC-Unique: yw9uQnqcOJaoVPnHOiD1DA-1 Received: by mail-pf1-f200.google.com with SMTP id l11so7326820pfc.16 for ; Tue, 22 Dec 2020 11:39:13 -0800 (PST) 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:user-agent; bh=5tsCMd9Nfdq9n0ayDvsC2lk0uNSEwrw9mxvuZSf1qkQ=; b=QHny63oIq3Tx2SSHMdHNZkfQJw4BkNAHeIVYJdvHuhCc+iEVHfHL1MK4DRJMHu5qz4 ie/99y0V3mWmzUfcHbqadXCQbYhvjqF8oaRrk1oo4R0PCWllFTys/PMCKSxr1Dwcdvme 5Dh8q9SEZTkypg4nTW/3s1JPcvU6UIvOH+rYzu+CghxVZxXC0590EvloGGi7rQgiyGZO Qra2CvpS+wEXWUO1gSomJAOBGoF4FI0GfdQnPeaJMcFCjfWKuO0vNulbzgRqlOXj25ik dp/MgezBarghGVbR0/BhbggD5KK0y2rah209EQYnZjBro7sQL1JO0BFy7gNzJQkpKV1b a2Ag== X-Gm-Message-State: AOAM5300XzOiq6TWEicEgg3y6TdA6P1bYu7AC3CqIRhIWDaYY9iFspQv zTCk1MLjuWVlgEK4cHPlqoklTwjZ6gXybpbumdP+ycS/9iwdksMGxMYWbahKlWtRgLpaxM11cI4 dF0WggPnMYEBCQOiXYneeMkvn X-Received: by 2002:a62:7857:0:b029:19d:fe6a:3069 with SMTP id t84-20020a6278570000b029019dfe6a3069mr21223284pfc.3.1608665952719; Tue, 22 Dec 2020 11:39:12 -0800 (PST) X-Google-Smtp-Source: ABdhPJxiytS6W//zDGdZqsS2j37qTS3snbiPRUfNBd0oZl7T0AOd+Z8EYMV0Xj4leWnaUJxCM0pRgQ== X-Received: by 2002:a62:7857:0:b029:19d:fe6a:3069 with SMTP id t84-20020a6278570000b029019dfe6a3069mr21223273pfc.3.1608665952512; Tue, 22 Dec 2020 11:39:12 -0800 (PST) Received: from xiangao.remote.csb ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 7sm21372646pfh.142.2020.12.22.11.39.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Dec 2020 11:39:12 -0800 (PST) Date: Wed, 23 Dec 2020 03:39:01 +0800 From: Gao Xiang To: Christoph Hellwig Cc: Huang Jianan , guoweichao@oppo.com, linux-erofs@lists.ozlabs.org, zhangshiming@oppo.com, linux-kernel@vger.kernel.org Subject: Re: [PATCH] erofs: support direct IO for uncompressed file Message-ID: <20201222193901.GA1892159@xiangao.remote.csb> References: <20201214140428.44944-1-huangjianan@oppo.com> <20201222142234.GB17056@infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20201222142234.GB17056@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Christoph, On Tue, Dec 22, 2020 at 02:22:34PM +0000, Christoph Hellwig wrote: > Please do not add new callers of __blockdev_direct_IO and use the modern > iomap variant instead. We've talked about this topic before. The current status is that iomap doesn't support tail-packing inline data yet (Chao once sent out a version), and erofs only cares about read intrastructure for now (So we don't think more about how to deal with tail-packing inline write path). Plus, the original patch was once lack of inline data regression test from gfs2 folks. The main use case I know so far is to enable direct I/O and leave loop images uncompressed for loop devices. And making the content of the loop images compressed to avoid double caching. Personally, I'd like to convert it to iomap infrastructure as well. So if it has some concern for __blockdev_direct_IO as an interim solution, hope that Jianan could pick this work up. That would be better. Thanks, Gao Xiang > 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=-5.0 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,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 3735CC433E0 for ; Tue, 22 Dec 2020 19:39:28 +0000 (UTC) Received: from lists.ozlabs.org (lists.ozlabs.org [203.11.71.2]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 930C22333B for ; Tue, 22 Dec 2020 19:39:27 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 930C22333B Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=redhat.com Authentication-Results: mail.kernel.org; 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Tue, 22 Dec 2020 11:39:12 -0800 (PST) X-Google-Smtp-Source: ABdhPJxiytS6W//zDGdZqsS2j37qTS3snbiPRUfNBd0oZl7T0AOd+Z8EYMV0Xj4leWnaUJxCM0pRgQ== X-Received: by 2002:a62:7857:0:b029:19d:fe6a:3069 with SMTP id t84-20020a6278570000b029019dfe6a3069mr21223273pfc.3.1608665952512; Tue, 22 Dec 2020 11:39:12 -0800 (PST) Received: from xiangao.remote.csb ([209.132.188.80]) by smtp.gmail.com with ESMTPSA id 7sm21372646pfh.142.2020.12.22.11.39.08 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Tue, 22 Dec 2020 11:39:12 -0800 (PST) Date: Wed, 23 Dec 2020 03:39:01 +0800 From: Gao Xiang To: Christoph Hellwig Subject: Re: [PATCH] erofs: support direct IO for uncompressed file Message-ID: <20201222193901.GA1892159@xiangao.remote.csb> References: <20201214140428.44944-1-huangjianan@oppo.com> <20201222142234.GB17056@infradead.org> MIME-Version: 1.0 In-Reply-To: <20201222142234.GB17056@infradead.org> User-Agent: Mutt/1.10.1 (2018-07-13) Authentication-Results: relay.mimecast.com; auth=pass smtp.auth=CUSA124A263 smtp.mailfrom=hsiangkao@redhat.com X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=utf-8 Content-Disposition: inline X-BeenThere: linux-erofs@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Development of Linux EROFS file system List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-kernel@vger.kernel.org, guoweichao@oppo.com, linux-erofs@lists.ozlabs.org, zhangshiming@oppo.com Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" Hi Christoph, On Tue, Dec 22, 2020 at 02:22:34PM +0000, Christoph Hellwig wrote: > Please do not add new callers of __blockdev_direct_IO and use the modern > iomap variant instead. We've talked about this topic before. The current status is that iomap doesn't support tail-packing inline data yet (Chao once sent out a version), and erofs only cares about read intrastructure for now (So we don't think more about how to deal with tail-packing inline write path). Plus, the original patch was once lack of inline data regression test from gfs2 folks. The main use case I know so far is to enable direct I/O and leave loop images uncompressed for loop devices. And making the content of the loop images compressed to avoid double caching. Personally, I'd like to convert it to iomap infrastructure as well. So if it has some concern for __blockdev_direct_IO as an interim solution, hope that Jianan could pick this work up. That would be better. Thanks, Gao Xiang >