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Date: Tue, 26 Nov 2024 11:33:51 +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,
	Christoph Hellwig <hch@lst.de>
Subject: Re: [PATCH] block: Prevent potential deadlock in
 blk_revalidate_disk_zones()
Message-ID: <20241126103351.GA16537@lst.de>
References: <20241126085342.173158-1-dlemoal@kernel.org>
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User-Agent: Mutt/1.5.17 (2007-11-01)

On Tue, Nov 26, 2024 at 05:53:42PM +0900, Damien Le Moal wrote:
> in disk_update_zone_resources(). disk_free_zone_resources() is also
> modified to operate with the queue frozen as before by adding calls to
> blk_mq_freeze_queue() and blk_mq_unfreeze_queue().

This now adds a queue freeze to disk_release for zoned device, which
previously didn't have it.  Given that at this point no I/O on the
disk is possible, and the freezes are quite expensive that's probably
not a good idea.

> -	blk_mq_freeze_queue(q);
>  	if (ret > 0)
>  		ret = disk_update_zone_resources(disk, &args);
>  	else
>  		pr_warn("%s: failed to revalidate zones\n", disk->disk_name);
>  	if (ret)
>  		disk_free_zone_resources(disk);
> -	blk_mq_unfreeze_queue(q);

So for a minimal version you could keep the freezing here.