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=-3.8 required=3.0 tests=BAYES_00,DKIM_INVALID, DKIM_SIGNED,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS 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 34914C433E3 for ; Tue, 21 Jul 2020 15:52:09 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 118CD2073A for ; Tue, 21 Jul 2020 15:52:09 +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="RyAh1b+A" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728219AbgGUPwH (ORCPT ); Tue, 21 Jul 2020 11:52:07 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38964 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726029AbgGUPwH (ORCPT ); Tue, 21 Jul 2020 11:52:07 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id EE82FC061794; Tue, 21 Jul 2020 08:52:06 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=infradead.org; s=casper.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; bh=CmlEdM9mHmEYsnkNRDmtewDs+LTuThNYW1KeG9HP9QA=; b=RyAh1b+Aew+y8wPFyVvKx99p4o 7LllldkBFIeFA/7lpj4qE89gQWwfUtJzVTUyprOec/KJ7Orn8V2fo1kYc44pMh6XskT/tbs5S3mhT ke5HgkEX7NuIqfCeVZzvhGugdguxIRFc5l7O1rkzh6CBGGu6Rsk4Dc/MatzZIsphuKpwBCCWzyZBD kayZ1Pd1P23pCWewHEm0Gz1yywn76NKHLMik4zLhCY7Nrcaiz3jpyj5qSSOIk9ACUDApGX1nCiXPl HfShmHDDH5e1hx6MIq6NzR5vxxJH9BRKV4y0VplaZ6m//vUwYdXFL4yQncyLwbQXcH7zeojPyQlVx EAc+PtFA==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxuYj-00054a-SC; Tue, 21 Jul 2020 15:52:02 +0000 Date: Tue, 21 Jul 2020 16:52:01 +0100 From: Matthew Wilcox To: Christoph Hellwig Cc: Goldwyn Rodrigues , Dave Chinner , Damien Le Moal , Naohiro Aota , Johannes Thumshirn , linux-btrfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, cluster-devel@redhat.com, linux-ext4@vger.kernel.org, linux-xfs@vger.kernel.org, Michael Kerrisk , linux-man@vger.kernel.org Subject: Re: RFC: iomap write invalidation Message-ID: <20200721155201.GL15516@casper.infradead.org> References: <20200713074633.875946-1-hch@lst.de> <20200720215125.bfz7geaftocy4r5l@fiona> <20200721145313.GA9217@lst.de> <20200721150432.GH15516@casper.infradead.org> <20200721150615.GA10330@lst.de> <20200721151437.GI15516@casper.infradead.org> <20200721151616.GA11074@lst.de> <20200721153136.GJ15516@casper.infradead.org> <20200721154240.GB11652@lst.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200721154240.GB11652@lst.de> Sender: linux-fsdevel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On Tue, Jul 21, 2020 at 05:42:40PM +0200, Christoph Hellwig wrote: > On Tue, Jul 21, 2020 at 04:31:36PM +0100, Matthew Wilcox wrote: > > > Umm, no. -ENOTBLK is internal - the file systems will retry using > > > buffered I/O and the error shall never escape to userspace (or even the > > > VFS for that matter). > > > > Ah, I made the mistake of believing the comments that I could see in > > your patch instead of reading the code. > > > > Can I suggest deleting this comment: > > > > /* > > * No fallback to buffered IO on errors for XFS, direct IO will either > > * complete fully or fail. > > */ > > > > and rewording this one: > > > > /* > > * Allow a directio write to fall back to a buffered > > * write *only* in the case that we're doing a reflink > > * CoW. In all other directio scenarios we do not > > * allow an operation to fall back to buffered mode. > > */ > > > > as part of your revised patchset? > > That isn't actually true. In current mainline we only fallback on > reflink RMW cases, but with this series we also fall back for > invalidation failures. ... that's why I'm suggesting that you delete the first one and rewrite the second one. Because they aren't true.