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=-2.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS,USER_AGENT_SANE_1 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 C3A7DC43140 for ; Thu, 5 Sep 2019 20:28:10 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EA07E20692 for ; Thu, 5 Sep 2019 20:28:10 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2390294AbfIEU2J (ORCPT ); Thu, 5 Sep 2019 16:28:09 -0400 Received: from mx2.suse.de ([195.135.220.15]:54042 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1731823AbfIEU2J (ORCPT ); Thu, 5 Sep 2019 16:28:09 -0400 X-Virus-Scanned: by amavisd-new at test-mx.suse.de Received: from relay2.suse.de (unknown [195.135.220.254]) by mx1.suse.de (Postfix) with ESMTP id CF16FAC64; Thu, 5 Sep 2019 20:28:07 +0000 (UTC) Date: Thu, 5 Sep 2019 15:28:05 -0500 From: Goldwyn Rodrigues To: Christoph Hellwig Cc: linux-fsdevel@vger.kernel.org, linux-btrfs@vger.kernel.org, darrick.wong@oracle.com, linux-xfs@vger.kernel.org, Goldwyn Rodrigues Subject: Re: [PATCH 02/15] iomap: Read page from srcmap if IOMAP_F_COW is set Message-ID: <20190905202805.nhhmsyiicnyeaeuy@fiona> References: <20190905150650.21089-1-rgoldwyn@suse.de> <20190905150650.21089-3-rgoldwyn@suse.de> <20190905163756.GA22883@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190905163756.GA22883@lst.de> User-Agent: NeoMutt/20180716 Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 18:37 05/09, Christoph Hellwig wrote: > On Thu, Sep 05, 2019 at 10:06:37AM -0500, Goldwyn Rodrigues wrote: > > - else if (iomap->flags & IOMAP_F_BUFFER_HEAD) > > + } else if (iomap->flags & IOMAP_F_COW) { > > + if (WARN_ON_ONCE(iomap->flags & IOMAP_F_BUFFER_HEAD)) { > > + status = -EIO; > > + goto out_no_page; > > + } > > + if (WARN_ON_ONCE(srcmap->type == IOMAP_HOLE && > > + srcmap->addr != IOMAP_NULL_ADDR)) { > > Well, we want HOLES to have IOMAP_NULL_ADDR everywhere, so not sure > why the assert is just here. This came up as one of the review comments for checking srcmap. This does look ugly after taking out iomap_assert(). Removing. > > > + status = -EIO; > > + goto out_no_page; > > + } > > + status = __iomap_write_begin(inode, pos, len, page, srcmap); > > + } else if (iomap->flags & IOMAP_F_BUFFER_HEAD) { > > status = __block_write_begin_int(page, pos, len, NULL, iomap); > > - else > > + } else { > > status = __iomap_write_begin(inode, pos, len, page, iomap); > > + } > > Maybe a good way to structure this is: > > if (iomap->flags & IOMAP_F_BUFFER_HEAD) { > if (WARN_ON_ONCE(iomap->flags & IOMAP_F_COW)) { > status = -EIO; > goto out_no_page; > } > status = __block_write_begin_int(page, pos, len, NULL, iomap); > } else { > status = __iomap_write_begin(inode, pos, len, page, > (iomap->flags & IOMAP_F_COW) ? srcmap : iomap); > } Yes, this looks much better. Will incorporate. -- Goldwyn