1 files changed, 18 insertions, 17 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 2f8578fb89ff..ffe824782647 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -328,7 +328,7 @@ void scsi_device_unbusy(struct scsi_device *sdev, struct scsi_cmnd *cmd)
 	if (starget->can_queue > 0)
 		atomic_dec(&starget->target_busy);
 
-	atomic_dec(&sdev->device_busy);
+	sbitmap_put(&sdev->budget_map, cmd->budget_token);
 	cmd->budget_token = -1;
 }
 
@@ -1257,19 +1257,20 @@ scsi_device_state_check(struct scsi_device *sdev, struct request *req)
 }
 
 /*
- * scsi_dev_queue_ready: if we can send requests to sdev, return 1 else
- * return 0.
- *
- * Called with the queue_lock held.
+ * scsi_dev_queue_ready: if we can send requests to sdev, assign one token
+ * and return the token else return -1.
  */
 static inline int scsi_dev_queue_ready(struct request_queue *q,
 				  struct scsi_device *sdev)
 {
-	unsigned int busy;
+	int token;
 
-	busy = atomic_inc_return(&sdev->device_busy) - 1;
+	token = sbitmap_get(&sdev->budget_map);
 	if (atomic_read(&sdev->device_blocked)) {
-		if (busy)
+		if (token < 0)
+			goto out;
+
+		if (scsi_device_busy(sdev) > 1)
 			goto out_dec;
 
 		/*
@@ -1281,13 +1282,12 @@ static inline int scsi_dev_queue_ready(struct request_queue *q,
 				   "unblocking device at zero depth\n"));
 	}
 
-	if (busy >= sdev->queue_depth)
-		goto out_dec;
-
-	return 1;
+	return token;
 out_dec:
-	atomic_dec(&sdev->device_busy);
-	return 0;
+	if (token >= 0)
+		sbitmap_put(&sdev->budget_map, token);
+out:
+	return -1;
 }
 
 /*
@@ -1612,15 +1612,16 @@ static void scsi_mq_put_budget(struct request_queue *q, int budget_token)
 {
 	struct scsi_device *sdev = q->queuedata;
 
-	atomic_dec(&sdev->device_busy);
+	sbitmap_put(&sdev->budget_map, budget_token);
 }
 
 static int scsi_mq_get_budget(struct request_queue *q)
 {
 	struct scsi_device *sdev = q->queuedata;
+	int token = scsi_dev_queue_ready(q, sdev);
 
-	if (scsi_dev_queue_ready(q, sdev))
-		return 0;
+	if (token >= 0)
+		return token;
 
 	atomic_inc(&sdev->restarts);