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 58DD93002B9
	for <linux-kernel@vger.kernel.org>; Fri,  6 Mar 2026 14:24:39 +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=1772807080; cv=none; b=RbNOT/KmAowvJCbaoV+MepeiG0VlSUp1235BaXdip40xtLwLYzYBD3Pa/zcRU0naUfdEoxG2yTCZykjC+GbHzS1N1OtWqNEEWQ4FO4egf0+3stsiwKVmPx+1RSXKfFjm/4SByyQ+VVz3wq3cJM3jbb+2QPH+PnzR7f5wS6+M0Vc=
ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org;
	s=arc-20240116; t=1772807080; c=relaxed/simple;
	bh=EjalZ5zBoRD5jbwJyHVnj6qUq6tCtAHtWVHVjCoiOOU=;
	h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version:
	 Content-Type:Content-Disposition:In-Reply-To; b=U84HY/IUBkA8eoCU/UXIy8hl/CgU/P6pixzcewfeEVqmZj/ERggODyjdG6gztyVM+p7JEFwIK2VKXhxy2xG9qbkjoicviJkgcgcq2gMbZuzVw9uBUyP9uM2tc1QHkE+/iyofr6RUQQHGTnyp5mEqkBHU8KBVoYHrpCRrH8mXfTs=
ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (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=pass (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 7F3CB68B05; Fri,  6 Mar 2026 15:24:34 +0100 (CET)
Date: Fri, 6 Mar 2026 15:24:34 +0100
From: Christoph Hellwig <hch@lst.de>
To: Robert Pang <robertpang@google.com>
Cc: Keith Busch <kbusch@kernel.org>, Jens Axboe <axboe@kernel.dk>,
	Christoph Hellwig <hch@lst.de>, Sagi Grimberg <sagi@grimberg.me>,
	Zhang Yi <yi.zhang@huaweicloud.com>, bmarzins@redhat.com,
	brauner@kernel.org, chaitanyak@nvidia.com, chengzhihao1@huawei.com,
	djwong@kernel.org, john.g.garry@oracle.com,
	martin.petersen@oracle.com, shinichiro.kawasaki@wdc.com,
	tytso@mit.edu, yangerkun@huawei.com, yi.zhang@huawei.com,
	yukuai3@huawei.com, linux-nvme@lists.infradead.org,
	linux-kernel@vger.kernel.org
Subject: Re: [PATCH] nvme: honor NVME_QUIRK_DEALLOCATE_ZEROES for unmap
 Write Zeroes
Message-ID: <20260306142434.GB16612@lst.de>
References: <20260305202735.1773922-1-robertpang@google.com>
Precedence: bulk
X-Mailing-List: linux-kernel@vger.kernel.org
List-Id: <linux-kernel.vger.kernel.org>
List-Subscribe: <mailto:linux-kernel+subscribe@vger.kernel.org>
List-Unsubscribe: <mailto:linux-kernel+unsubscribe@vger.kernel.org>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <20260305202735.1773922-1-robertpang@google.com>
User-Agent: Mutt/1.5.17 (2007-11-01)

On Thu, Mar 05, 2026 at 12:27:32PM -0800, Robert Pang wrote:
> However, certain devices already use the NVME_QUIRK_DEALLOCATE_ZEROES quirk to
> indicate that they deterministically return zeroes after a deallocate/discard

Those certain devices are completely obsolete first generation Intel
SSDs.

> Update nvme_update_disk_info() to allow the presence of the DEALLOCATE_ZEROES
> quirk (combined with DSM support) to set max_hw_wzeroes_unmap_sectors to enable

No. This was a hack that got sneaked in in the first days of the nvme
driver and never should have been there.  It most certainly should not
be extended to any new functionality.