remove a few uses of ->queuedata

[Dan Williams]

On Fri, May 8, 2020 at 9:16 AM Christoph Hellwig <hch at lst.de> wrote:
>
> Hi all,
>
> various bio based drivers use queue->queuedata despite already having
> set up disk->private_data, which can be used just as easily.  This
> series cleans them up to only use a single private data pointer.

...but isn't the queue pretty much guaranteed to be cache hot and the
gendisk cache cold? I'm not immediately seeing what else needs the
gendisk in the I/O path. Is there another motivation I'm missing?