On Wed, Feb 8, 2017 at 2:23 AM, Jan Kara [off-list ref] wrote:

On Wed 08-02-17 08:51:42, Jan Kara wrote:

[..]

<DETOUR BEGIN>
This ordering seems to be the real culprit of the bdi name reuse problems
Omar has reported? Same as described in commit 6cd18e711dd8 for MD BTW and
Dan's patch could be IMHO replaced by a move of bdi_unregister() from
blk_cleanup_queue() to del_gendisk() where it logically belongs as a
counterpart of device_add_disk(). I'll test that.
<DETOUR END>

I'd support that change. This is is why I called my fix "brute-force",
it just accommodated the existing problematic ordering.