[PATCH 2/2] nvme: don't freeze/unfreeze queues from different contexts

[Keith Busch]

On Tue, Jun 13, 2023 at 08:58:47AM +0800, Ming Lei wrote:
> And this way is correct because quiesce is enough for driver to handle
> error recovery. The only difference is where to wait during error recovery.
> With this way, IO is just queued in block layer queue instead of
> __bio_queue_enter(), finally waiting for completion is done in upper
> layer. Either way, IO can't move on during error recovery.

The point was to contain the fallout from modifying the hctx mappings.
If you allow IO to queue in the blk-mq layer while a reset is in
progress, they may be entering a context that won't be as expected on
the other side of the reset.