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 14ED5C55199 for ; Mon, 27 Apr 2020 05:55:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id E97AB2075B for ; Mon, 27 Apr 2020 05:55:43 +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="OUvliz3A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726434AbgD0Fzk (ORCPT ); Mon, 27 Apr 2020 01:55:40 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38692 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-FAIL-OK-FAIL) by vger.kernel.org with ESMTP id S1726221AbgD0Fzk (ORCPT ); Mon, 27 Apr 2020 01:55:40 -0400 Received: from bombadil.infradead.org (bombadil.infradead.org [IPv6:2607:7c80:54:e::133]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 5CB4EC061A0F; Sun, 26 Apr 2020 22:55:40 -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=R3+pbJIQteflo4uZ0aWi5kA4IXjwF0WSfqzTyP9nDZg=; b=OUvliz3ACGuJUvGnnk2irZ8Szf 9mbtz2wa6iso5Tmx8uHxbTcc5bK75uyEgtUyHO9bYMO6d9++UD8fKtQaSSHI7F0RO01IgnnrKrjxe Y6kY8Y0/Tpyz0sWBIo/Lkzxy9aO3E4QOvDjNGizxw1uwrMF53voV7aFTSzqJmpiXYURbw0jLz0SaS OMjV0MyEmIDXJoiRzUp65JvWRAc3qbuM44hKw5K6yzrggdfV/AJ1PuzY87hnexeytyes6F4F0Ics9 8oHSLZIheBvCMwKDGTTjDSsCrgYJulBU3fvLUgxmvQ0ws5gVr8S+8e7lJ0atbqiyVHZpTZFhCvWh6 i7BtMSRg==; Received: from hch by bombadil.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jSwk0-0007pN-6J; Mon, 27 Apr 2020 05:55:40 +0000 Date: Sun, 26 Apr 2020 22:55:40 -0700 From: Christoph Hellwig To: Matthew Wilcox Cc: Guoqing Jiang , linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, hch@infradead.org, david@fromorbit.com, "Darrick J. Wong" , linux-xfs@vger.kernel.org Subject: Re: [RFC PATCH 6/9] iomap: use set/clear_fs_page_private Message-ID: <20200427055540.GC16709@infradead.org> References: <20200426214925.10970-1-guoqing.jiang@cloud.ionos.com> <20200426214925.10970-7-guoqing.jiang@cloud.ionos.com> <20200427002631.GC29705@bombadil.infradead.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200427002631.GC29705@bombadil.infradead.org> 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 Sun, Apr 26, 2020 at 05:26:31PM -0700, Matthew Wilcox wrote: > On Sun, Apr 26, 2020 at 11:49:22PM +0200, Guoqing Jiang wrote: > > @@ -59,24 +59,18 @@ iomap_page_create(struct inode *inode, struct page *page) > > * migrate_page_move_mapping() assumes that pages with private data have > > * their count elevated by 1. > > */ > > - get_page(page); > > - set_page_private(page, (unsigned long)iop); > > - SetPagePrivate(page); > > - return iop; > > + return (struct iomap_page *)set_fs_page_private(page, iop); > > } > > This cast is unnecessary. void * will be automatically cast to the > appropriate pointer type. I also find the pattern eather strange. A: attach_page_private(page, iop); return iop; explains the intent much better.