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 E170CC433E0 for ; Tue, 21 Jul 2020 15:31:42 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B7F92206E9 for ; Tue, 21 Jul 2020 15:31:42 +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="BFZGeujw" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728609AbgGUPbl (ORCPT ); Tue, 21 Jul 2020 11:31:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:35808 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726654AbgGUPbl (ORCPT ); Tue, 21 Jul 2020 11:31:41 -0400 Received: from casper.infradead.org (casper.infradead.org [IPv6:2001:8b0:10b:1236::1]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 23BD5C061794; Tue, 21 Jul 2020 08:31:41 -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=3+Pp/3FagpQxAvNMEgqYtXBdoVkPujJ1lGmtP9vdIiU=; b=BFZGeujwgBNxHNSd3GsPXLbs2u 0whuAeYJh8B7UmJm1CKmOH/uPtfZwcSCjo0xFvKy+Qe0rZXWVTAHVicNwUY6cVJKCd43ia3UsYiQB 44rFLiF2gMMCJ/B8w84DXAY4I46N0iYAP4RZ59K0gMxkgINTjQ4K3pRNrGaisthtTKi8t5g8RM3iJ U+YnZbfG7dpY+6j12QMS5pOXVPf3b2+WY+4YAOu6cm/OSO+l31X3wTDzq+rsqa5PRWnfdHE1u3I9+ fBK7wZqM2yjOcKdDLDA19hq1B4esBkxg0oUs/1nHdBCKcosscvXRRq/Ib/2CJNa+urQHz5GK9kXhR bHeRqntQ==; Received: from willy by casper.infradead.org with local (Exim 4.92.3 #3 (Red Hat Linux)) id 1jxuEy-0003u2-6C; Tue, 21 Jul 2020 15:31:36 +0000 Date: Tue, 21 Jul 2020 16:31:36 +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: <20200721153136.GJ15516@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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200721151616.GA11074@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 05:16:16PM +0200, Christoph Hellwig wrote: > On Tue, Jul 21, 2020 at 04:14:37PM +0100, Matthew Wilcox wrote: > > On Tue, Jul 21, 2020 at 05:06:15PM +0200, Christoph Hellwig wrote: > > > On Tue, Jul 21, 2020 at 04:04:32PM +0100, Matthew Wilcox wrote: > > > > I thought you were going to respin this with EREMCHG changed to ENOTBLK? > > > > > > Oh, true. I'll do that ASAP. > > > > Michael, could we add this to manpages? > > 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?