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 7A8FBEED603 for ; Thu, 12 Sep 2024 13:18:12 +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=wtgi72iuYtGZ9IDF1f6CCII4BRCc85UODAgzqjvcCpg=; b=sRxkLt348E5jd+NN+QaWvptGuM jFLDz5RN3BZKT0rmNejBqo3p/VXrCsa48BR9mD0VOSnc7c8txm46mxle4LqoEETCFCkonsP31RfP9 GfNPVuR13L4/dkmoYW1J+lNi1I6lP9SPR/OXhAxbX4cAgRO1bZTVBPmE3vr25vsfKpgd9f7O9BclZ W9rOg/B1T06sOZVG0HdigZ2JAUU1w67mzNfCidb8oGNy2+X1HCd4LoXX251BUJkKox5lWxRVrbyeE oVJQCwIyhDOks9sNRWqAfkyx+zSYd+YNnjXh1dshf5rpPUbNOx0xdbVekde5mkysAUiGMs2hqbmm0 EVEzszkg==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1soji6-0000000DAyo-1hKz; Thu, 12 Sep 2024 13:18:10 +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 1soji2-0000000DAxG-0ZTp for linux-nvme@lists.infradead.org; Thu, 12 Sep 2024 13:18:08 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 88577227AB5; Thu, 12 Sep 2024 15:18:03 +0200 (CEST) Date: Thu, 12 Sep 2024 15:18:03 +0200 From: Christoph Hellwig To: John Garry Cc: axboe@kernel.dk, song@kernel.org, yukuai3@huawei.com, kbusch@kernel.org, hch@lst.de, 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: <20240912131803.GD29641@lst.de> References: <20240903150748.2179966-1-john.g.garry@oracle.com> <20240903150748.2179966-5-john.g.garry@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20240903150748.2179966-5-john.g.garry@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_061806_339705_1EFE7341 X-CRM114-Status: GOOD ( 13.47 ) 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 Tue, Sep 03, 2024 at 03:07:48PM +0000, John Garry wrote: > if (sectors < bio_sectors(bio)) { > - struct bio *split = bio_split(bio, sectors, GFP_NOIO, > + struct bio *split; > + > + if (bio->bi_opf & REQ_ATOMIC) > + return false; I guess this is the erroring out when attempting to split the request. Can you add a comment to explain that and why it can't happen for the normal I/O patterns?