Re: [PATCH 1/4] blk-mq: update comment for blk_mq_quiesce_queue_nowait()

[Christoph Hellwig]

On Tue, Nov 01, 2022 at 11:11:34PM +0800, Jinlong Chen wrote:
> blk_mq_quiesce_queue_nowait() is now reasonably used by scsi_host_block()
> to avoid calling synchronize_rcu() for each LUN. We should not consider to
> remove it.

I strongly disagree about this being a reasonable use.  What SCSI did
there is a horrible hack that should have never been merged.  The
right thing to do is the per-tag_set quiesce that we've been working
on.