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 bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.lore.kernel.org (Postfix) with ESMTPS id E2A44EED613 for ; Thu, 12 Sep 2024 15:10:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20210309; h=Sender:List-Subscribe:List-Help :List-Post:List-Archive:List-Unsubscribe:List-Id:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=o4u1ad0XaOz6dku3BHvync+SagiBct8oraEeiniHSdg=; b=pgFHB6TjRQarjyADBO0zQVxVnL X4K065iyJetr5XlusC8r4jQh/1EB4oTt3CNzEPMUqveD9Xk/B6ud3NTrX10H8SANvAvamOEEDW2sk fL8aGtPJ+Vr//Y8u5fdnFxyebyR1kjPn9OgRcKshiaTlMVWPM6g4SqumgtJ761VBYliU3lw/VV+PB dohuz2jfWmO8tSspHOf4ONOhyThtFV5VbcNU2krN8DacYS8FAOBo+4duMenQYv133S4wvzLP/Hx4y cAZBBc0CcD66/GBUgFfD2lCDLwyVk5NGoesnH6g0/4CC2WnvOvbjpfYkM6Fe0E4pr4xjeo8vx+DWB TCiG+9Jg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1solT4-0000000DUWm-0jB1; Thu, 12 Sep 2024 15:10:46 +0000 Received: from verein.lst.de ([213.95.11.211]) by bombadil.infradead.org with esmtps (Exim 4.97.1 #2 (Red Hat Linux)) id 1solT1-0000000DUVR-2qSy for linux-nvme@lists.infradead.org; Thu, 12 Sep 2024 15:10:45 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id A577D227AAF; Thu, 12 Sep 2024 17:10:38 +0200 (CEST) Date: Thu, 12 Sep 2024 17:10:38 +0200 From: Christoph Hellwig To: John Garry Cc: Christoph Hellwig , axboe@kernel.dk, song@kernel.org, yukuai3@huawei.com, kbusch@kernel.org, sagi@grimberg.me, James.Bottomley@HansenPartnership.com, martin.petersen@oracle.com, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org, linux-nvme@lists.infradead.org, linux-scsi@vger.kernel.org Subject: Re: [PATCH RFC 4/4] md/raid0: Atomic write support Message-ID: <20240912151038.GA5858@lst.de> References: <20240903150748.2179966-1-john.g.garry@oracle.com> <20240903150748.2179966-5-john.g.garry@oracle.com> <20240912131803.GD29641@lst.de> <340e4306-4442-4276-b420-6fee8ed97a7e@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <340e4306-4442-4276-b420-6fee8ed97a7e@oracle.com> User-Agent: Mutt/1.5.17 (2007-11-01) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20240912_081043_881179_CC0BD55F X-CRM114-Status: GOOD ( 13.95 ) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.34 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Thu, Sep 12, 2024 at 03:48:09PM +0100, John Garry wrote: > > I actually now think that I should change bio_split() to return NULL for > splitting a REQ_ATOMIC, like what do for ZONE_APPEND - calling bio_split() > like this is a common pattern in md RAID personalities. However, none of > the md RAID code check for a NULL split, which they really should, so I can > make that change also. bio_split is a bit of a mess - even NULL isn't very good at returning what caused it to fail. Maybe a switch to ERR_PTR and an audit of all callers might be a good idea.