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 vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 60B58C77B7F for ; Fri, 19 May 2023 08:49:53 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231169AbjESItw (ORCPT ); Fri, 19 May 2023 04:49:52 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38658 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229769AbjESItp (ORCPT ); Fri, 19 May 2023 04:49:45 -0400 Received: from us-smtp-delivery-124.mimecast.com (us-smtp-delivery-124.mimecast.com [170.10.133.124]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 120D710F9 for ; Fri, 19 May 2023 01:48:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=redhat.com; s=mimecast20190719; t=1684486134; 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=NFfz1Qefawb0lyg57CVn7ptvHTdohZyit/vKaHZw8LE=; b=OyXk8N3SJHsS/2vxdcu82WGZIFUH/9kzeKSPoSpDJ5iZ8rowGE9l8WAQgzSuRn5jpuspmL 8zMYybiXvb6x3QCgtx2jnTfIQ6XUFaSsMGaU7Y5cM3dp75TEVqgxYnxKaQq9iMDe8bdlnl 4lWpYTR73JWH7TIslrKct83lKHdYavA= Received: from mimecast-mx02.redhat.com (mimecast-mx02.redhat.com [66.187.233.88]) by relay.mimecast.com with ESMTP with STARTTLS (version=TLSv1.2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id us-mta-176-PtzYX2HQN1GxCR941SWFpg-1; Fri, 19 May 2023 04:48:51 -0400 X-MC-Unique: PtzYX2HQN1GxCR941SWFpg-1 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.rdu2.redhat.com [10.11.54.4]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mimecast-mx02.redhat.com (Postfix) with ESMTPS id 485DC80120A; Fri, 19 May 2023 08:48:50 +0000 (UTC) Received: from warthog.procyon.org.uk (unknown [10.42.28.221]) by smtp.corp.redhat.com (Postfix) with ESMTP id 9E8842026D49; Fri, 19 May 2023 08:48:47 +0000 (UTC) Organization: Red Hat UK Ltd. Registered Address: Red Hat UK Ltd, Amberley Place, 107-111 Peascod Street, Windsor, Berkshire, SI4 1TE, United Kingdom. Registered in England and Wales under Company Registration No. 3798903 From: David Howells In-Reply-To: References: <20230519074047.1739879-1-dhowells@redhat.com> <20230519074047.1739879-6-dhowells@redhat.com> To: Christoph Hellwig Cc: dhowells@redhat.com, Jens Axboe , Al Viro , Matthew Wilcox , Jan Kara , Jeff Layton , David Hildenbrand , Jason Gunthorpe , Logan Gunthorpe , Hillf Danton , Christian Brauner , Linus Torvalds , linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, Christoph Hellwig , linux-erofs@lists.ozlabs.org, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org Subject: Re: [PATCH v20 05/32] splice: Make splice from a DAX file use direct_splice_read() MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-ID: <1742242.1684486127.1@warthog.procyon.org.uk> Date: Fri, 19 May 2023 09:48:47 +0100 Message-ID: <1742243.1684486127@warthog.procyon.org.uk> X-Scanned-By: MIMEDefang 3.1 on 10.11.54.4 Precedence: bulk List-ID: X-Mailing-List: linux-xfs@vger.kernel.org Christoph Hellwig wrote: > On Fri, May 19, 2023 at 08:40:20AM +0100, David Howells wrote: > > +#ifdef CONFIG_FS_DAX > > + if (IS_DAX(in->f_mapping->host)) > > No need for the ifdef. IS_DAX is compile-time false if CONFIG_FS_DAX > is not set. Ah - it's not that IS_DAX() is conditionalised, it's that S_DAX is. There's a bunch of places that use CONFIG_FS_DAX blocks, but I guess that's because they include calls to functions that are conditionalised out. I wonder if the dax_iomap_rw() declaration in the header can have a non-DAX fallback that returns an error and then we can get rid of some of the other conditionalisation. David