On Wed, Sep 19, 2018 at 11:52:21AM +0800, jianchao.wang wrote:

Hi Ming

On 09/18/2018 08:15 PM, Ming Lei wrote:

quoted

The adminq request can be quisced in the scsi_device level, just as normal IO
request, because the scsi_device instance is same with normal IO.

Yes, the scsi_queue_rq->scsi_prep_state_check could gate things out of.

quoted

But in blk-mq level, this admin queue won't be quiesced or frozen at all.

But the scsi_queue_rq/scsi_request_fn will be invoked, right ?

This is different from the original implementation.

For legacy path, as you mentioned, scsi_prep_fn() will work, then
scsi_request_fn() won't be called.

For blk-mq, scsi_queue_rq() is always called, and that is a bit
different, but the result is fine given admin request is submitted
much less frequently.

Thanks,
Ming