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Date: Mon, 6 Jan 2025 09:31:29 +0100
From: Christoph Hellwig <hch@lst.de>
To: Damien Le Moal <dlemoal@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>, linux-block@vger.kernel.org,
	linux-nvme@lists.infradead.org, Christoph Hellwig <hch@lst.de>,
	Keith Busch <kbusch@kernel.org>, Sagi Grimberg <sagi@grimberg.me>,
	Ming Lei <ming.lei@redhat.com>, Nilay Shroff <nilay@linux.ibm.com>
Subject: Re: [PATCH 3/3] nvme: Fix queue freeze and limits lock order
Message-ID: <20250106083129.GE18408@lst.de>
References: <20250104132522.247376-1-dlemoal@kernel.org> <20250104132522.247376-4-dlemoal@kernel.org>
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On Sat, Jan 04, 2025 at 10:25:22PM +0900, Damien Le Moal wrote:
> Modify the functions nvme_update_ns_info_generic(),
> nvme_update_ns_info_block() and nvme_update_ns_info() to freeze a
> namespace queue using blk_mq_freeze_queue() after starting the queue
> limits update with queue_limits_start_update() so that the queue
> freezing is always done after obtaining the device queue limits lock (as
> per the block layer convention for sysfs attributes).

FYI, there's a few more like this.  In my WIP series I've basically
made the normal queue_limits_commit_update contain the freeze and add
a special version without the freeze, which makes a lot of this
more obvious.  Let me dust it off even before sorting out the poll
flag so that we have a little more discussion material.