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 kanga.kvack.org (kanga.kvack.org [205.233.56.17]) by smtp.lore.kernel.org (Postfix) with ESMTP id 3D1C5C00528 for ; Fri, 21 Jul 2023 06:24:31 +0000 (UTC) Received: by kanga.kvack.org (Postfix) id C17E528019A; Fri, 21 Jul 2023 02:24:30 -0400 (EDT) Received: by kanga.kvack.org (Postfix, from userid 40) id BC93D280190; Fri, 21 Jul 2023 02:24:30 -0400 (EDT) X-Delivered-To: int-list-linux-mm@kvack.org Received: by kanga.kvack.org (Postfix, from userid 63042) id AB8A828019A; Fri, 21 Jul 2023 02:24:30 -0400 (EDT) X-Delivered-To: linux-mm@kvack.org Received: from relay.hostedemail.com (smtprelay0014.hostedemail.com [216.40.44.14]) by kanga.kvack.org (Postfix) with ESMTP id 9B716280190 for ; Fri, 21 Jul 2023 02:24:30 -0400 (EDT) Received: from smtpin22.hostedemail.com (a10.router.float.18 [10.200.18.1]) by unirelay07.hostedemail.com (Postfix) with ESMTP id 64E3B16017B for ; Fri, 21 Jul 2023 06:24:30 +0000 (UTC) X-FDA: 81034629900.22.B3B9B19 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) by imf19.hostedemail.com (Postfix) with ESMTP id 6F3811A0012 for ; Fri, 21 Jul 2023 06:24:28 +0000 (UTC) Authentication-Results: imf19.hostedemail.com; dkim=none; dmarc=none; spf=none (imf19.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; d=hostedemail.com; s=arc-20220608; t=1689920668; h=from:from:sender:reply-to:subject:subject:date:date: message-id:message-id:to:to:cc:cc:mime-version:mime-version: content-type:content-type:content-transfer-encoding: in-reply-to:in-reply-to:references:references; bh=H2d7cKo/xGgxsqHcuiRtSCMScpJWW1L8N0rzeIq8Dj0=; b=X1RTeVK/CW7BSSPU/ZKqpmbKm2+iinqf9jLp34/w8plZJRw39LbQYCSNm4BZTXzUva4c+w lxKqNhfOkVVhQwcnXHkb/9bV71xx58kx7gtaOWNs+qtHFaqhaQLWSfjLXyAUah05jqIMFg stHFOaSz/QkPIhb2Hn3hZJ2EGdO7Hyc= ARC-Authentication-Results: i=1; imf19.hostedemail.com; dkim=none; dmarc=none; spf=none (imf19.hostedemail.com: domain of hch@lst.de has no SPF policy when checking 213.95.11.211) smtp.mailfrom=hch@lst.de ARC-Seal: i=1; s=arc-20220608; d=hostedemail.com; t=1689920668; a=rsa-sha256; cv=none; b=Rdvm03grg38ymoKRItorbLVhYV579LIUxGlBjemPqB2MYB4lz72LQaxCZ29X6xGJd8+tUo epmr39YICJyU9t0hYlT4oJDuzwmr9so7FmAfWz8rvrwvTCNp4U7+XEowzh5dz2OzMOWuRg fnUFpMKBI5GxKu3ZND0RvR8/NkfbmZ8= Received: by verein.lst.de (Postfix, from userid 2407) id 8D3CB6732D; Fri, 21 Jul 2023 08:24:23 +0200 (CEST) Date: Fri, 21 Jul 2023 08:24:23 +0200 From: Christoph Hellwig To: Matthew Wilcox Cc: Christoph Hellwig , Jens Axboe , "Darrick J. Wong" , Andrew Morton , Christian Brauner , linux-block@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-xfs@vger.kernel.org, linux-mm@kvack.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 6/6] fs: add CONFIG_BUFFER_HEAD Message-ID: <20230721062423.GA20845@lst.de> References: <20230720140452.63817-1-hch@lst.de> <20230720140452.63817-7-hch@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.17 (2007-11-01) X-Rspamd-Queue-Id: 6F3811A0012 X-Rspam-User: X-Rspamd-Server: rspam04 X-Stat-Signature: 674ryhujrie6zay6f6onfm5qg5ufw4bw X-HE-Tag: 1689920668-220024 X-HE-Meta: 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 /SLNZ/Mi noKYSn647jJ+TNxURNOtnGi7zbG1XrHaeSRd1jefOwd9u/+CkaJonFKqb0Ml5+jtXJA9yBkSXR+q6BOUvCmfOCiqbqv8O2+cMSvlD X-Bogosity: Ham, tests=bogofilter, spamicity=0.000000, version=1.2.4 Sender: owner-linux-mm@kvack.org Precedence: bulk X-Loop: owner-majordomo@kvack.org List-ID: On Thu, Jul 20, 2023 at 03:45:11PM +0100, Matthew Wilcox wrote: > On Thu, Jul 20, 2023 at 04:04:52PM +0200, Christoph Hellwig wrote: > > @@ -400,7 +391,8 @@ static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, > > iomap->type = IOMAP_MAPPED; > > iomap->addr = iomap->offset; > > iomap->length = isize - iomap->offset; > > - iomap->flags |= IOMAP_F_BUFFER_HEAD; > > + if (IS_ENABLED(CONFIG_BUFFER_HEAD)) > > + iomap->flags |= IOMAP_F_BUFFER_HEAD; > > Wouldn't it be simpler to do ... > > +#ifdef CONFIG_BUFFER_HEAD > #define IOMAP_F_BUFFER_HEAD (1U << 4) > +#else > +#define IOMAP_F_BUFFER_HEAD 0 > +#endif > > in include/linux/iomap.h ? > ... because this function then goes away. I guess we could do that. It is less intrusive, but I have to say I find flags that get defined away to 0 fairly confusing for the reader.