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Date:   Mon, 21 Nov 2022 08:02:44 +0100
From:   Christoph Hellwig <hch@lst.de>
To:     Al Viro <viro@zeniv.linux.org.uk>
Cc:     Christoph Hellwig <hch@lst.de>, Jens Axboe <axboe@kernel.dk>,
        Eric Biggers <ebiggers@kernel.org>, linux-block@vger.kernel.org
Subject: Re: untangle the request_queue refcounting from the queue kobject
 v2
Message-ID: <20221121070244.GA23563@lst.de>
References: <20221114042637.1009333-1-hch@lst.de> <Y3g9P8NB+ubuKaqA@ZenIV>
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On Sat, Nov 19, 2022 at 02:19:43AM +0000, Al Viro wrote:
> > Changes since v1:
> >  - also change the blk_crypto_sysfs_unregister prototype
> >  - add two patches to fix the error handling in blk_register_queue
> 
> Umm...  Do we ever want access to queue parameters of the stuff that has
> a queue, but no associated gendisk?  SCSI tape, for example...

What do you mean with "access queue parameters"?  The sysfs access can
since day one only happen through the queue.

> 	Re refcounting: AFAICS, blk_mq_alloc_disk_for_queue() is broken.
> __alloc_disk_node() consumes queue reference (and stuffs it into gendisk->queue)
> on success; on failure it leaves the reference alone.  E.g. this

Yes, it needs a put_queue for the error handler.