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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 552B4C433EF for ; Fri, 1 Jul 2022 14:35:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232445AbiGAOfm (ORCPT ); Fri, 1 Jul 2022 10:35:42 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55072 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232735AbiGAOf2 (ORCPT ); Fri, 1 Jul 2022 10:35:28 -0400 Received: from mail-pg1-x529.google.com (mail-pg1-x529.google.com [IPv6:2607:f8b0:4864:20::529]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D4E2D3EAB3 for ; Fri, 1 Jul 2022 07:30:54 -0700 (PDT) Received: by mail-pg1-x529.google.com with SMTP id s206so2570088pgs.3 for ; Fri, 01 Jul 2022 07:30:54 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel-dk.20210112.gappssmtp.com; s=20210112; h=message-id:date:mime-version:user-agent:subject:content-language :from:to:cc:references:in-reply-to:content-transfer-encoding; bh=lcUts9IRbHMoYKbUwXCQXdwgQkjG8wAgntfc6a84Bzk=; b=i6JialmZiw+wHNeAvHcpKTIFr0MYcZSBWHyK9ku4aQu3UocWa79NsyyNmyZAjZxLXF PMHTN+aMRiS9m/Lc5x3K/0diosTPQEjG9P4lx2GzEHd3O3fCe5ICdFvFa6XC1rDYWjgF fB5sKKdLorSL3/BvShteEZ3YsoJ48nKfHxDDemnRRPRIh6srncHNrCp41yl9zFfzTa3e gZGArV8NlySbiki+wKdD4rOi91oUEacsZ+akcux088FMB07dPkgxgtN0Lz3RIoRSwKlD Fhr18qgexDLlJy9/2meoYDpr0YQSga9XJllO/448ogR2uD5X8Am0GB3TJw6ZNKjTJWxS LWdg== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20210112; h=x-gm-message-state:message-id:date:mime-version:user-agent:subject :content-language:from:to:cc:references:in-reply-to :content-transfer-encoding; bh=lcUts9IRbHMoYKbUwXCQXdwgQkjG8wAgntfc6a84Bzk=; b=pOp6S93srcIyktOQE8/4zeWTjs4Ch72eUFXILOpHCIRTSWzyHfArXmIIJD7cTeP/tA dBKrDGkrab5Ul9y/RqItNyrSrVt513A7iP7i+O/nZQSMJLFVmhRzoTdcmYQOKzq2USxq RInc363zLkcO9R3IX/rMgis8Ej60UG1kwgFWXUc6PW1dk3XtYxkwmmORQWLanBys1cNx 9yDrOPDI1XbI/srT+ratU2HL7CFtVedbmUVN7aYKP/oN+83YpyBja8ncFWi0KAtxyHXg fx+hWUFCOKQnmwaDjZU+F5RGVAYKtJdHRTSLf6RJT6K3QKCBANUQVU5IZQt58w/osAlN FSlQ== X-Gm-Message-State: AJIora9WJ9SgK8Qexe7YMTdqP3v4H0FoWMPAGtmUA5bDeoSk8IdbY3p5 TrJpczAXOBp1LU4ykSsKVDe7DQ== X-Google-Smtp-Source: AGRyM1uh4FYNuZr5eq7SjLg0KSqYaKNNix56AAXCr8IAjyfrw3Y704ctiVNZiyUFZK8dp7vB5+ohjQ== X-Received: by 2002:a63:1047:0:b0:40d:7553:d897 with SMTP id 7-20020a631047000000b0040d7553d897mr12334549pgq.485.1656685854229; Fri, 01 Jul 2022 07:30:54 -0700 (PDT) Received: from [192.168.1.100] ([198.8.77.157]) by smtp.gmail.com with ESMTPSA id u3-20020a170903108300b0016a613012a0sm15494212pld.210.2022.07.01.07.30.53 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Fri, 01 Jul 2022 07:30:53 -0700 (PDT) Message-ID: Date: Fri, 1 Jul 2022 08:30:52 -0600 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux aarch64; rv:91.0) Gecko/20100101 Thunderbird/91.10.0 Subject: Re: [PATCH v7 15/15] xfs: Add async buffered write support Content-Language: en-US From: Jens Axboe To: Al Viro , Stefan Roesch Cc: io-uring@vger.kernel.org, kernel-team@fb.com, linux-mm@kvack.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, david@fromorbit.com, jack@suse.cz, hch@infradead.org, Christoph Hellwig References: <20220601210141.3773402-1-shr@fb.com> <20220601210141.3773402-16-shr@fb.com> <0a75a0c4-e2e5-b403-27bc-e43872fecdc1@kernel.dk> In-Reply-To: <0a75a0c4-e2e5-b403-27bc-e43872fecdc1@kernel.dk> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-fsdevel@vger.kernel.org On 7/1/22 8:19 AM, Jens Axboe wrote: > On 6/30/22 10:39 PM, Al Viro wrote: >> On Wed, Jun 01, 2022 at 02:01:41PM -0700, Stefan Roesch wrote: >>> This adds the async buffered write support to XFS. For async buffered >>> write requests, the request will return -EAGAIN if the ilock cannot be >>> obtained immediately. >> >> breaks generic/471... > > That test case is odd, because it makes some weird assumptions about > what RWF_NOWAIT means. Most notably that it makes it mean if we should > instantiate blocks or not. Where did those assumed semantics come from? > On the read side, we have clearly documented that it should "not wait > for data which is not immediately available". > > Now it is possible that we're returning a spurious -EAGAIN here when we > should not be. And that would be a bug imho. I'll dig in and see what's > going on. This is the timestamp update that needs doing which will now return -EAGAIN if IOCB_NOWAIT is set as it may block. I do wonder if we should just allow inode time updates with IOCB_NOWAIT, even on the io_uring side. Either that, or passed in RWF_NOWAIT semantics don't map completely to internal IOCB_NOWAIT semantics. At least in terms of what generic/471 is doing, but I'm not sure who came up with that and if it's established semantics or just some made up ones from whomever wrote that test. I don't think they make any sense, to be honest. -- Jens Axboe