[RFC PATCH v1] sd: drain a request queue during sd_shutdown()

[Lee Sang Hyun <sh425.lee@xxxxxxxxxxx>]

Need to set a request queue like below in sd_shutdown()
to prevent pending IOs before UFS shutdown.

Change-Id: I2818cf95944d85baa50b626fcf538f19d06d6d54
Signed-off-by: Lee Sang Hyun <sh425.lee@xxxxxxxxxxx>
---
 drivers/scsi/sd.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index d90feff..7418d27 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -3564,6 +3564,8 @@ static int sd_start_stop_device(struct scsi_disk *sdkp, int start)
 static void sd_shutdown(struct device *dev)
 {
 	struct scsi_disk *sdkp = dev_get_drvdata(dev);
+	struct request_queue *q = sdp->request_queue;
+	unsigned long flags;
 
 	if (!sdkp)
 		return;         /* this can happen */
@@ -3580,6 +3582,12 @@ static void sd_shutdown(struct device *dev)
 		sd_printk(KERN_NOTICE, sdkp, "Stopping disk\n");
 		sd_start_stop_device(sdkp, 0);
 	}
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	queue_flag_set(QUEUE_FLAG_DYING, q);
+	__blk_drain_queue(q, true);
+	queue_flag_set(QUEUE_FLAG_DEAD, q);
+	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 
 static int sd_suspend_common(struct device *dev, bool ignore_stop_errors)
-- 
2.7.4