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=-0.6 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,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 AB6A6C54FD0 for ; Mon, 27 Apr 2020 05:52:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 7BC522075B for ; Mon, 27 Apr 2020 05:52:58 +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="Lm4Tu30h" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726541AbgD0Fw5 (ORCPT ); Mon, 27 Apr 2020 01:52:57 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38272 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726221AbgD0Fw5 (ORCPT ); Mon, 27 Apr 2020 01:52:57 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 42D63C061A0F; Sun, 26 Apr 2020 22:52:57 -0700 (PDT) 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; bh=LQVtzGaomYtG7V/jX0MqKImKPB9VkLmtjmhmXgAH0Xc=; b=Lm4Tu30hpSl+D6HEWWAScRDmtt jEUap9jlU3mOipiBhzFXsGaa0TyCihkJXduNfgNxTU2yikcSbjuO3C4cIv4/T11IisHHZto5q8uGh sKJ6gECuN90WXQKLegzyzObDogzxAEQ9Gpi1co4E8SVbc4VbwrhnKfFg4B+a3szinI8z/eh3/mcXt gfK34E4urHi205PEvNFymGPB6mQ/MaCRwFZ4yrb6ga62i397JNSdkPDnMjtReS1ytuDrBSH8EDF/c TYWbj5yjm5MUJTtj2/7APAB2btVxovtErHyhdesBTGK3Mt+n14gARrO3Zy8fREzDu8qD3e515MWIK tjryPzJA==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jSwhL-0004dg-5C; Mon, 27 Apr 2020 05:52:55 +0000 Date: Sun, 26 Apr 2020 22:52:55 -0700 From: Christoph Hellwig To: Guoqing Jiang Cc: linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, david@fromorbit.com, willy@infradead.org, Andrew Morton , "Darrick J. Wong" , William Kucharski , "Kirill A. Shutemov" , Andreas Gruenbacher , Yang Shi , Yafang Shao Subject: Re: [RFC PATCH 1/9] include/linux/pagemap.h: introduce set/clear_fs_page_private Message-ID: <20200427055255.GA16709@infradead.org> References: <20200426214925.10970-1-guoqing.jiang@cloud.ionos.com> <20200426214925.10970-2-guoqing.jiang@cloud.ionos.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200426214925.10970-2-guoqing.jiang@cloud.ionos.com> X-SRS-Rewrite: SMTP reverse-path rewritten from by bombadil.infradead.org. See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Why not attach_page_private and clear_page_private as that conveys the use case a little better? > +static inline void *set_fs_page_private(struct page *page, void *data) > +{ > + get_page(page); > + set_page_private(page, (unsigned long)data); > + SetPagePrivate(page); > + > + return data; > +} > + > +static inline void *clear_fs_page_private(struct page *page) > +{ > + void *data = (void *)page_private(page); > + > + if (!PagePrivate(page)) > + return NULL; > + ClearPagePrivate(page); > + set_page_private(page, 0); > + put_page(page); > + > + return data; > +} Can you add kerneldoc comments describing them, including why we take the refernces? Also what is the point of the return value of set_fs_page_private?