On 06/06/2017 09:21 AM, Ming Lei wrote:

Hi,

There is one big issue in current blk_mq_quiesce_queue():

    - in case of direct issue or BLK_MQ_S_START_ON_RUN, dispatch won't
    be prevented after blk_mq_quiesce_queue() is returned.


The 1st two patches fix two problems in direct issue, please consider
it for v4.12.

The other 10 patches improves blk_mq_quiesce_queue(), and
make is easy to use, and avoid race between queue restart and
quiescing. These 10 patches should be for v4.13.

I've added 1-2 for 4.12, I'll review the rest for 4.13 when some
cycles free up.

-- 
Jens Axboe