[PATCH 1/4] blk-mq: add API of blk_mq_unfreeze_queue_force

[Keith Busch]

On Thu, Jun 15, 2023 at 10:32:33PM +0800, Ming Lei wrote:
> NVMe calls freeze/unfreeze in different contexts, and controller removal
> may break in-progress error recovery, then leave queues in frozen state.
> So cause IO hang in del_gendisk() because pending writeback IOs are
> still waited in bio_queue_enter().

Shouldn't those writebacks be unblocked by the existing check in
bio_queue_enter, test_bit(GD_DEAD, &disk->state))? Or are we missing a
disk state update or wakeup on this condition?