Hi all, this series uses the approach from Tetsuo to delay the destroy_workueue call, extended by a delayed teardown of the workers to fix a potential race window then the workqueue can be still round after finishing the commands. Changes since v4: - keep the (questionable) __invalidate_device call in nbd as-is for now - suppress uevents while reconfiguring Changes since v3: - change bd_openers into a atomic_t, including a bunch of cleanups and fix found while adding those Changes since v2: - rebased to the lastest block for-next tree, which has the async clear reverted and ->free_disk - impkement ->free_disk for loop to handle open vs delete races more gracefully - get rid of lo_refcnt entirely Changes since v1: - add comments to document the lo_refcnt synchronization - fix comment typos
