[PATCH v3 4/6] scsi: Set QUEUE_FLAG_PREEMPT_ONLY while quiesced

[Bart Van Assche]

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

Signed-off-by: Bart Van Assche <bart.vanass...@wdc.com>
Cc: Martin K. Petersen <martin.peter...@oracle.com>
Cc: Ming Lei <ming....@redhat.com>
Cc: Christoph Hellwig <h...@lst.de>
Cc: Hannes Reinecke <h...@suse.com>
Cc: Johannes Thumshirn <jthumsh...@suse.de>
---
 drivers/scsi/scsi_lib.c | 11 ++++++++---
 1 file changed, 8 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62f905b22821..ca84fd2d93ea 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -2927,19 +2927,22 @@ static void scsi_wait_for_queuecommand(struct 
scsi_device *sdev)
 int
 scsi_device_quiesce(struct scsi_device *sdev)
 {
+       struct request_queue *q = sdev->request_queue;
        int err;
 
        mutex_lock(&sdev->state_mutex);
        err = scsi_device_set_state(sdev, SDEV_QUIESCE);
+       if (err == 0)
+               blk_set_preempt_only(q, true);
        mutex_unlock(&sdev->state_mutex);
 
        if (err)
                return err;
 
-       scsi_run_queue(sdev->request_queue);
+       scsi_run_queue(q);
        while (atomic_read(&sdev->device_busy)) {
                msleep_interruptible(200);
-               scsi_run_queue(sdev->request_queue);
+               scsi_run_queue(q);
        }
        return 0;
 }
@@ -2962,8 +2965,10 @@ 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_set_preempt_only(sdev->request_queue, false);
                scsi_run_queue(sdev->request_queue);
+       }
        mutex_unlock(&sdev->state_mutex);
 }
 EXPORT_SYMBOL(scsi_device_resume);
-- 
2.14.1