From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wr0-f199.google.com (mail-wr0-f199.google.com [209.85.128.199]) by kanga.kvack.org (Postfix) with ESMTP id 993186B0003 for ; Tue, 22 May 2018 04:15:23 -0400 (EDT) Received: by mail-wr0-f199.google.com with SMTP id f23-v6so13475441wra.20 for ; Tue, 22 May 2018 01:15:23 -0700 (PDT) Received: from newverein.lst.de (verein.lst.de. [213.95.11.211]) by mx.google.com with ESMTPS id j124-v6si11288908wmd.185.2018.05.22.01.15.22 for (version=TLS1_2 cipher=ECDHE-RSA-AES128-GCM-SHA256 bits=128/128); Tue, 22 May 2018 01:15:22 -0700 (PDT) Date: Tue, 22 May 2018 10:20:36 +0200 From: Christoph Hellwig Subject: Re: [PATCH 16/34] iomap: add initial support for writes without buffer heads Message-ID: <20180522082036.GA9801@lst.de> References: <20180518164830.1552-1-hch@lst.de> <20180518164830.1552-17-hch@lst.de> <20180521232700.GB14384@magnolia> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180521232700.GB14384@magnolia> Sender: owner-linux-mm@kvack.org List-ID: To: "Darrick J. Wong" Cc: Christoph Hellwig , linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org, linux-mm@kvack.org On Mon, May 21, 2018 at 04:27:00PM -0700, Darrick J. Wong wrote: > Something doesn't smell right here. The only pages we need to read in > are the first and last pages in the write_begin range, and only if they > aren't page aligned and the underlying extent is IOMAP_MAPPED, right? Yes, and I'm pretty sure I did get this right before refactoring everything for sub-blocksize support.