Make the quiesce state visible to the block layer for the next
patch in this series.

Signed-off-by: Bart Van Assche <[email protected]>
Reviewed-by: Christoph Hellwig <[email protected]>
Cc: Martin K. Petersen <[email protected]>
Cc: Ming Lei <[email protected]>
Cc: Hannes Reinecke <[email protected]>
Cc: Johannes Thumshirn <[email protected]>
---
 drivers/scsi/scsi_lib.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e0bef5c9dd14..534c81de0880 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2940,8 +2940,16 @@ scsi_device_quiesce(struct scsi_device *sdev)
        if (freeze)
                blk_mq_freeze_queue(q);
        err = scsi_device_set_state(sdev, SDEV_QUIESCE);
+       if (err == 0)
+               blk_set_preempt_only(q);
        mutex_unlock(&sdev->state_mutex);
 
+       /*
+        * Ensure that the effect of blk_set_preempt_only() is globally
+        * visible before unfreezing the queue.
+        */
+       if (err == 0)
+               synchronize_rcu();
        if (freeze)
                blk_mq_unfreeze_queue(q);
 
@@ -2966,8 +2974,10 @@ void scsi_device_resume(struct scsi_device *sdev)
         */
        mutex_lock(&sdev->state_mutex);
        if (sdev->sdev_state == SDEV_QUIESCE &&
-           scsi_device_set_state(sdev, SDEV_RUNNING) == 0)
+           scsi_device_set_state(sdev, SDEV_RUNNING) == 0) {
+               blk_clear_preempt_only(sdev->request_queue);
                scsi_run_queue(sdev->request_queue);
+       }
        mutex_unlock(&sdev->state_mutex);
 }
 EXPORT_SYMBOL(scsi_device_resume);
-- 
2.14.1

Reply via email to