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Date:   Mon, 24 May 2021 09:29:50 +0200
From:   Christoph Hellwig <hch@lst.de>
To:     Hannes Reinecke <hare@suse.de>
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Subject: Re: [PATCH 18/26] nvme-multipath: convert to
 blk_alloc_disk/blk_cleanup_disk
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On Sun, May 23, 2021 at 10:20:27AM +0200, Hannes Reinecke wrote:
> What about the check for GENHD_FL_UP a bit further up in line 766?
> Can this still happen with the new allocation scheme, ie is there still a 
> difference in lifetime between ->disk and ->disk->queue?

Yes, nvme_free_ns_head can still be called before device_add_disk was
called for an allocated nshead gendisk during error handling of the
setup path.  There is still a difference in the lifetime in that they
are separately refcounted, but it does not matter to the driver.