From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from verein.lst.de (verein.lst.de [213.95.11.211]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 8C43A4BABE; Mon, 29 Jan 2024 06:20:41 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=213.95.11.211 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706509243; cv=none; b=jBNiESgIhefzXuVHaz/dmCZdXx471c2h8nt0EE/IMxpDYoN7MB/CJFHGzbpIMtYbjrZhMH1xQn52uelbGNcyG/kBwYfviJvszYebJwEfHJ/SKxOQFVrou5MwGqk/D73S8Ic0tmnw2q+YYQxdzT7AY5YX2HiSeQ4oC87pP9CDJ9U= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1706509243; c=relaxed/simple; bh=a3ABtJCzIyYgu9Y0K7TLjoHutY0PL9Nh7ra7xgZiwb4=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=OiFXPqE1frxXp7p6hj25V3Go63XbrKIkR0L69FTxxskll67ow6MDlZNakiiC0JqYEqt6twCUs+DSqQFPJ1HGMZxJESlkzBiXI4JSgDH8Kw4BWlClrlvZBHKhR/nYoDKZdowXf/mxO4/17stK+4XSgtOtWNnukjjKxLdAAgUiqAU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de; spf=pass smtp.mailfrom=lst.de; arc=none smtp.client-ip=213.95.11.211 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=lst.de 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> Precedence: bulk X-Mailing-List: linux-xfs@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: 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) 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.