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 C02F1C47422 for ; Mon, 29 Jan 2024 06:20:43 +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=vSx5jpmmLEewlonMu1sE/caa7FmbXF5z9XALmJJ8S2U=; b=n/wuLNJJGhaCRL5j4X/1X3FEDG DcqRwkXDxZVUgy/rZiDXQsq/Iqpvzq5smdGkUBSpia3GCZ0jIhNA+209GgtC1E9wBKbRFB7ljDjx0 Z4cOdt/2l66JHUh4g1roHV3TOAE6mIQl1SpfeZRpRPI9FSwUNrnl+tcqdLX4386Zqx7nkeWa2pNsW tfiEElYVmJDSwv/bwH1wCerm46Lc3BQ5PlSD2k1FxmrLP3mnS//ytkM4F+OU6G5K2nNRbuAzDlHi7 HSaftnEpSKcEyDMTUbp2aOmp951ClpD1RhG4aYaK07giaxkQdSAH7DaZrgy4elnTVq6gL74UwfNot 74wfj37A==; Received: from localhost ([::1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.97.1 #2 (Red Hat Linux)) id 1rUL0d-0000000BRLp-1GNL; Mon, 29 Jan 2024 06:20:43 +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 1rUL0Z-0000000BRLP-3TUb for linux-nvme@lists.infradead.org; Mon, 29 Jan 2024 06:20:41 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 95A9768B05; Mon, 29 Jan 2024 07:20:35 +0100 (CET) Date: Mon, 29 Jan 2024 07:20:35 +0100 From: Christoph Hellwig To: John Garry Cc: Keith Busch , axboe@kernel.dk, hch@lst.de, sagi@grimberg.me, jejb@linux.ibm.com, martin.petersen@oracle.com, djwong@kernel.org, viro@zeniv.linux.org.uk, brauner@kernel.org, dchinner@redhat.com, jack@suse.cz, linux-block@vger.kernel.org, linux-kernel@vger.kernel.org, linux-nvme@lists.infradead.org, linux-xfs@vger.kernel.org, linux-fsdevel@vger.kernel.org, tytso@mit.edu, jbongio@google.com, linux-scsi@vger.kernel.org, ming.lei@redhat.com, ojaswin@linux.ibm.com, bvanassche@acm.org, Alan Adamson Subject: Re: [PATCH v3 15/15] nvme: Ensure atomic writes will be executed atomically Message-ID: <20240129062035.GB19796@lst.de> References: <20240124113841.31824-1-john.g.garry@oracle.com> <20240124113841.31824-16-john.g.garry@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: 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-20240128_222040_050810_86A05BBD X-CRM114-Status: GOOD ( 16.14 ) 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, Jan 25, 2024 at 11:28:22AM +0000, John Garry wrote: > We have limits checks in XFS iomap and fops.c, but we would also want to > ensure that the the block layer is not doing anything it shouldn't be doing > after submit_bio_noacct(), like merging atomic write BIOs which straddle a > boundary or exceed atomic_max (if there were any merging). > > The SCSI standard already has provision for error'ing an atomic write > command which exceeds the target atomic write capabilities, while NVMe > doesn't. Can you get Oracle to propose this for NVMe? It always helps if these suggestions come from a large buyer of NVMe equipment. > BTW, Christoph did mention that he would like to see this: > https://lore.kernel.org/linux-nvme/20231109153603.GA2188@lst.de/ I can probably live with a sufficiently low-level block layer check.