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=-2.1 required=3.0 tests=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 D2ACCC3A59B for ; Fri, 30 Aug 2019 16:42:33 +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 529C32087F for ; Fri, 30 Aug 2019 16:42:33 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Nb5baDLH" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 529C32087F Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=pass smtp.mailfrom=linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Received: from bilbo.ozlabs.org (lists.ozlabs.org [IPv6:2401:3900:2:1::3]) by lists.ozlabs.org (Postfix) with ESMTP id 46KldL3LNzzDr34 for ; Sat, 31 Aug 2019 02:42:30 +1000 (AEST) Authentication-Results: lists.ozlabs.org; spf=none (mailfrom) smtp.mailfrom=bombadil.srs.infradead.org (client-ip=2607:7c80:54:e::133; helo=bombadil.infradead.org; envelope-from=batv+b0e6514120785512acaa+5850+infradead.org+hch@bombadil.srs.infradead.org; receiver=) Authentication-Results: lists.ozlabs.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: lists.ozlabs.org; dkim=pass (2048-bit key; unprotected) header.d=infradead.org header.i=@infradead.org header.b="Nb5baDLH"; dkim-atps=neutral Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (2048 bits) server-digest SHA256) (No client certificate requested) by lists.ozlabs.org (Postfix) with ESMTPS id 46KldB1Z9jzDqQP for ; Sat, 31 Aug 2019 02:42:22 +1000 (AEST) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=zT6Sffc7p6dXxr/DqLVZuPlm0esCLyE+d/3ikz+/jqI=; b=Nb5baDLHs6tOVMnZ2y1xUxHzs MhSwjOCDGxy8BvtXnOfjEW35qlNWyTbB5J8UoRl4zzLn+YSkRG+J46vsn972X8NpB8I7gKz1i1ZcD Bi2JWKJq4ZUANCc0oWI11+X0jE7gzpS3IFc1UfQGoD9Mk+ov4ZRJqRweV6Ek2FRGvomWDP7hd3ryu oaPu2QpDsqEh4GwblDsXtaPgKEHbndclLqmmnGyF5+5JhqE/2wMWTx6zkz1YCrd3bEALL5KVNQKUQ WpHREdtO/JtxBC5fHQ2repjFQJhEBNYaFxOJln6YisDqgjlMrFlhxRGO4FqgfssIOHIyKIy5OFC+0 f9lySr1Cg==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1i3jyP-0002rX-Ku; Fri, 30 Aug 2019 16:42:05 +0000 Date: Fri, 30 Aug 2019 09:42:05 -0700 From: Christoph Hellwig To: Gao Xiang Subject: Re: [PATCH v6 05/24] erofs: add inode operations Message-ID: <20190830164205.GD29603@infradead.org> References: <20190802125347.166018-1-gaoxiang25@huawei.com> <20190802125347.166018-6-gaoxiang25@huawei.com> <20190829102426.GE20598@infradead.org> <20190829115922.GG64893@architecture4> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829115922.GG64893@architecture4> User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html 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: Jan Kara , Dave Chinner , LKML , Miao Xie , devel@driverdev.osuosl.org, Stephen Rothwell , "Darrick J . Wong" , Christoph Hellwig , Linus Torvalds , Amir Goldstein , Alexander Viro , Jaegeuk Kim , Theodore Ts'o , Greg Kroah-Hartman , David Sterba , Pavel Machek , linux-fsdevel@vger.kernel.org, Andrew Morton , linux-erofs@lists.ozlabs.org Errors-To: linux-erofs-bounces+linux-erofs=archiver.kernel.org@lists.ozlabs.org Sender: "Linux-erofs" On Thu, Aug 29, 2019 at 07:59:22PM +0800, Gao Xiang wrote: > On Thu, Aug 29, 2019 at 03:24:26AM -0700, Christoph Hellwig wrote: > > [] > > > > > > + > > > + /* fill last page if inline data is available */ > > > + err = fill_inline_data(inode, data, ofs); > > > > Well, I think you should move the is_inode_flat_inline and > > (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) checks from that > > helper here, as otherwise you make everyone wonder why you'd always > > fill out the inline data. > > Currently, fill_inline_data() only fills for fast symlink, > later we can fill any tail-end block (such as dir block) > for our requirements. So change it when that later changes actually come in. And even then having the checks outside the function is a lot more obvious. > And I think that is minor. The problem is that each of these issues might appear minor on their own. But combined a lot of the coding style choices lead to code that is more suitable an obsfucated code contest than the Linux kernel as trying to understand even just a few places requires jumping through tons of helpers with misleading names and spread over various files. > The consideration is simply because iget_locked performs better > than iget5_locked. In what benchmark do the differences show up? 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=-2.1 required=3.0 tests=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 9B213C3A59B for ; Fri, 30 Aug 2019 16:42:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 71BB52087F for ; Fri, 30 Aug 2019 16:42:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=infradead.org header.i=@infradead.org header.b="Nb5baDLH" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728120AbfH3QmT (ORCPT ); Fri, 30 Aug 2019 12:42:19 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:49882 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727976AbfH3QmT (ORCPT ); Fri, 30 Aug 2019 12:42:19 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=bombadil.20170209; h=In-Reply-To:Content-Type:MIME-Version :References:Message-ID:Subject:Cc:To:From:Date:Sender:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=zT6Sffc7p6dXxr/DqLVZuPlm0esCLyE+d/3ikz+/jqI=; b=Nb5baDLHs6tOVMnZ2y1xUxHzs MhSwjOCDGxy8BvtXnOfjEW35qlNWyTbB5J8UoRl4zzLn+YSkRG+J46vsn972X8NpB8I7gKz1i1ZcD Bi2JWKJq4ZUANCc0oWI11+X0jE7gzpS3IFc1UfQGoD9Mk+ov4ZRJqRweV6Ek2FRGvomWDP7hd3ryu oaPu2QpDsqEh4GwblDsXtaPgKEHbndclLqmmnGyF5+5JhqE/2wMWTx6zkz1YCrd3bEALL5KVNQKUQ WpHREdtO/JtxBC5fHQ2repjFQJhEBNYaFxOJln6YisDqgjlMrFlhxRGO4FqgfssIOHIyKIy5OFC+0 f9lySr1Cg==; Received: from hch by bombadil.infradead.org with local (Exim 4.92 #3 (Red Hat Linux)) id 1i3jyP-0002rX-Ku; Fri, 30 Aug 2019 16:42:05 +0000 Date: Fri, 30 Aug 2019 09:42:05 -0700 From: Christoph Hellwig To: Gao Xiang Cc: Christoph Hellwig , Alexander Viro , Greg Kroah-Hartman , Andrew Morton , Stephen Rothwell , Theodore Ts'o , Pavel Machek , David Sterba , Amir Goldstein , "Darrick J . Wong" , Dave Chinner , Jaegeuk Kim , Jan Kara , Linus Torvalds , linux-fsdevel@vger.kernel.org, devel@driverdev.osuosl.org, LKML , linux-erofs@lists.ozlabs.org, Chao Yu , Miao Xie , Li Guifu , Fang Wei Subject: Re: [PATCH v6 05/24] erofs: add inode operations Message-ID: <20190830164205.GD29603@infradead.org> References: <20190802125347.166018-1-gaoxiang25@huawei.com> <20190802125347.166018-6-gaoxiang25@huawei.com> <20190829102426.GE20598@infradead.org> <20190829115922.GG64893@architecture4> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190829115922.GG64893@architecture4> User-Agent: Mutt/1.11.4 (2019-03-13) X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Thu, Aug 29, 2019 at 07:59:22PM +0800, Gao Xiang wrote: > On Thu, Aug 29, 2019 at 03:24:26AM -0700, Christoph Hellwig wrote: > > [] > > > > > > + > > > + /* fill last page if inline data is available */ > > > + err = fill_inline_data(inode, data, ofs); > > > > Well, I think you should move the is_inode_flat_inline and > > (S_ISLNK(inode->i_mode) && inode->i_size < PAGE_SIZE) checks from that > > helper here, as otherwise you make everyone wonder why you'd always > > fill out the inline data. > > Currently, fill_inline_data() only fills for fast symlink, > later we can fill any tail-end block (such as dir block) > for our requirements. So change it when that later changes actually come in. And even then having the checks outside the function is a lot more obvious. > And I think that is minor. The problem is that each of these issues might appear minor on their own. But combined a lot of the coding style choices lead to code that is more suitable an obsfucated code contest than the Linux kernel as trying to understand even just a few places requires jumping through tons of helpers with misleading names and spread over various files. > The consideration is simply because iget_locked performs better > than iget5_locked. In what benchmark do the differences show up?