[PATCH 5/8] blk-mq: add tagset quiesce interface

[Ming Lei]

On Thu, Oct 20, 2022 at 12:56:05PM +0200, Christoph Hellwig wrote:
> From: Chao Leng <lengchao at huawei.com>
> 
> Drivers that have shared tagsets may need to quiesce potentially a lot
> of request queues that all share a single tagset (e.g. nvme). Add an
> interface to quiesce all the queues on a given tagset. This interface is
> useful because it can speedup the quiesce by doing it in parallel.
> 
> Because some queues should not need to be quiesced(e.g. nvme connect_q)
> when quiesce the tagset. So introduce QUEUE_FLAG_SKIP_TAGSET_QUIESCE to
> tagset quiesce interface to skip the queue.
> 
> Signed-off-by: Chao Leng <lengchao at huawei.com>
> [hch: simplify for the per-tag_set srcu_struct]
> Signed-off-by: Christoph Hellwig <hch at lst.de>

Reviewed-by: Ming Lei <ming.lei at redhat.com>

Thanks,
Ming