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Date: Thu, 6 Jun 2024 07:52:51 -0700
From: Christoph Hellwig <hch@infradead.org>
To: Ming Lei <ming.lei@redhat.com>
Cc: yebin <yebin@huaweicloud.com>, Christoph Hellwig <hch@infradead.org>,
	axboe@kernel.dk, linux-block@vger.kernel.org,
	linux-kernel@vger.kernel.org, Ye Bin <yebin10@huawei.com>,
	Zhang Yi <yizhan@redhat.com>, "Ewan D. Milne" <emilne@redhat.com>,
	linux-nvme@lists.infradead.org
Subject: Re: [PATCH] block: bio-integrity: fix potential null-ptr-deref in
 bio_integrity_free
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References: <20240606062655.2185006-1-yebin@huaweicloud.com>
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 <66619EB6.4040002@huaweicloud.com>
 <ZmHH7mW0M80RaPlj@fedora>
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On Thu, Jun 06, 2024 at 10:30:06PM +0800, Ming Lei wrote:
> Yeah, that is one area queue freezing can't cover logical block size
> change, but I'd suggest to put the logical bs check into submit_bio() or
> slow path of __bio_queue_enter() at least.

We really need an alignment check in submit_bio anyway, so doing it
under the freeze protection would also help with this.

> My concern is that nvme format is started without draining IO, and
> IO can be submitted to hardware when nvme FW is handling formatting.
> I am not sure if nvme FW can deal with this situation correctly.
> Ewan suggested to run 'nvme format' with exclusive nvme disk open, which
> needs nvme-cli change.

.. and doesn't protect against someone using a different tool anyway.

That beeing said, nvme_passthru_start actually freezes all queues
based on the commands supported an affects log, and
nvme_init_known_nvm_effects should force this even for controllers
not supporting the log or reporting bogus information.  So in general
the queue should be frozen during the actual format.