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Date: Mon, 24 May 2021 09:25:57 +0200
From: Christoph Hellwig <hch@lst.de>
To: Hannes Reinecke <hare@suse.de>
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Cc: nvdimm@lists.linux.dev, Ulf Hansson <ulf.hansson@linaro.org>,
	Mike Snitzer <snitzer@redhat.com>,
	linux-nvme@lists.infradead.org, Song Liu <song@kernel.org>,
	dm-devel@redhat.com, linux-bcache@vger.kernel.org,
	Christoph Hellwig <hch@lst.de>, drbd-dev@lists.linbit.com,
	linux-s390@vger.kernel.org, Dave Jiang <dave.jiang@intel.com>,
	Maxim Levitsky <maximlevitsky@gmail.com>,
	Vishal Verma <vishal.l.verma@intel.com>,
	Christian Borntraeger <borntraeger@de.ibm.com>,
	Geert Uytterhoeven <geert@linux-m68k.org>,
	Matias Bjorling <mb@lightnvm.io>, Nitin Gupta <ngupta@vflare.org>,
	Vasily Gorbik <gor@linux.ibm.com>, linux-xtensa@linux-xtensa.org,
	Alex Dubov <oakad@yahoo.com>, Heiko Carstens <hca@linux.ibm.com>,
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	linux-m68k@lists.linux-m68k.org, Philip Kelleher <pjk1939@linux.ibm.com>,
	Dan Williams <dan.j.williams@intel.com>,
	Jens Axboe <axboe@kernel.dk>, Chris Zankel <chris@zankel.net>,
	linux-raid@vger.kernel.org, Max Filippov <jcmvbkbc@gmail.com>,
	linux-mmc@vger.kernel.org, Philipp Reisner <philipp.reisner@linbit.com>,
	Jim Paris <jim@jtan.com>, Minchan Kim <minchan@kernel.org>,
	Lars Ellenberg <lars.ellenberg@linbit.com>, linuxppc-dev@lists.ozlabs.org
Subject: Re: [Drbd-dev] [PATCH 13/26] dm: convert to
	blk_alloc_disk/blk_cleanup_disk
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On Sun, May 23, 2021 at 10:10:34AM +0200, Hannes Reinecke wrote:
> Can't these conditionals be merged into a single 'if (md->disk)'?
> Eg like:
>
> 	if (md->disk) {
> 		spin_lock(&_minor_lock);
> 		md->disk->private_data = NULL;
> 		spin_unlock(&_minor_lock);
> 		del_gendisk(md->disk);
> 		dm_queue_destroy_keyslot_manager(md->queue);
> 		blk_cleanup_disk(md->queue);
> 	}
>
> We're now always allocating 'md->disk' and 'md->queue' together,
> so how can we end up in a situation where one is set without the other?

I guess we could do that, not sure it is worth the churn, though.