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_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,T_DKIM_INVALID, USER_AGENT_MUTT autolearn=ham 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 89388C433F5 for ; Mon, 3 Sep 2018 04:50:18 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 3E39A20856 for ; Mon, 3 Sep 2018 04:50:18 +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="kdjpFoLh" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 3E39A20856 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=infradead.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726869AbeICJIl (ORCPT ); Mon, 3 Sep 2018 05:08:41 -0400 Received: from bombadil.infradead.org ([198.137.202.133]:57300 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725892AbeICJIl (ORCPT ); Mon, 3 Sep 2018 05:08:41 -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=xssHXQ9TFloh+QLsqre9b/6qtjcnjcD+GmpNadCPBy8=; b=kdjpFoLhERhb+vRc5Q0eIQW3j z0vSd1/ZcKFUP+es+fIToqFeu91wUiH8P6FOsh4Kqbado7YmKAl3CCaepb41ezMbxDEjg76gwSlmH k2DX/X9LVIAmJUi3cwDp9Lg2L26CMzyqyxnATSU/ecpE2DJcSAryNfyyknUlMtaOc9o892kY1/yym vc7YRU1Uc9THwUxGu8WQcEm8WaQtyPL51gGZYSj5hZB61BZjBMX9PaOqk2f8yT76/rbKEi/5+hAcd V3pwSXPDjauTMjVr1S6YdkiQGjidVZu8vyiHPdMK34gnGmJRg7VO+bJr79S9Bsx3zF+JWdXjwrtX/ QI/w3cakA==; Received: from willy by bombadil.infradead.org with local (Exim 4.90_1 #2 (Red Hat Linux)) id 1fwgo9-0004Zy-Iz; Mon, 03 Sep 2018 04:49:49 +0000 Date: Sun, 2 Sep 2018 21:49:49 -0700 From: Matthew Wilcox To: Souptick Joarder Cc: akpm@linux-foundation.org, konishi.ryusuke@lab.ntt.co.jp, viro@zeniv.linux.org.uk, tytso@mit.edu, adilger.kernel@dilger.ca, axboe@kernel.dk, darrick.wong@oracle.com, ebiggers@google.com, pombredanne@nexb.com, agruenba@redhat.com, gregkh@linuxfoundation.org, kemi.wang@intel.com, linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org, linux-ext4@vger.kernel.org, linux-nilfs@vger.kernel.org Subject: Re: [PATCH v2] fs: Convert return type int to vm_fault_t Message-ID: <20180903044949.GB17856@bombadil.infradead.org> References: <20180830172547.GA4408@jordon-HP-15-Notebook-PC> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180830172547.GA4408@jordon-HP-15-Notebook-PC> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Thu, Aug 30, 2018 at 10:55:47PM +0530, Souptick Joarder wrote: > +vm_fault_t block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, > + get_block_t get_block, int *err) I don't like returning both the errno and the vm_fault_t. To me that's a sign we need to rethink this interface. I have two suggestions. First, we could allocate a new VM_FAULT_NOSPC bit. Second, we could repurpose one of the existing bits, such as VM_FAULT_RETRY for this purpose. > -int ext4_page_mkwrite(struct vm_fault *vmf) > +vm_fault_t ext4_page_mkwrite(struct vm_fault *vmf) I also think perhaps we could start by _not_ converting block_page_mkwrite(). Just convert ext4_page_mkwrite(), and save converting block_page_mkwrite() for later.