On Fri, Sep 22, 2017 at 03:14:05PM -0700, Bart Van Assche wrote:
> Avoid that it can take 200 ms too long to wait for requests to
> finish. Note: blk_mq_freeze_queue() uses a wait queue to wait
> for ongoing requests to finish.
>
> Signed-off-by: Bart Van Assche <bart.vanassche@xxxxxxx>
> Cc: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
> Cc: Ming Lei <ming.lei@xxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>
> Cc: Hannes Reinecke <hare@xxxxxxxx>
> Cc: Johannes Thumshirn <jthumshirn@xxxxxxx>
> ---
> drivers/scsi/scsi_lib.c | 16 +++++++++++++---
> 1 file changed, 13 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
> index ca84fd2d93ea..c5e66bb0c94d 100644
> --- a/drivers/scsi/scsi_lib.c
> +++ b/drivers/scsi/scsi_lib.c
> @@ -2939,10 +2939,20 @@ scsi_device_quiesce(struct scsi_device *sdev)
> if (err)
> return err;
>
> - scsi_run_queue(q);
> - while (atomic_read(&sdev->device_busy)) {
> - msleep_interruptible(200);
> + if (q->mq_ops) {
> + /*
> + * Ensure write order of the PREEMPT_ONLY queue flag and
> + * q_usage_counter. See also blk_queue_enter().
> + */
> + smp_wmb();
> + blk_mq_freeze_queue(q);
> + blk_mq_unfreeze_queue(q);
> + } else {
> scsi_run_queue(q);
> + while (atomic_read(&sdev->device_busy)) {
> + msleep_interruptible(200);
> + scsi_run_queue(q);
> + }
Again, your patch doesn't fix scsi quiesce issue
on block legacy, either on suspend path or revalidate
path of transport spi.
--
Ming
