Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi into master

Pull SCSI fix from James Bottomley:
 "Small core patch to fix a corner case bug: we forgot to run the queues
  to handle starvation in the error exit from the scsi_queue_rq routine,
  which can lead to hangs on error conditions"

* tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi:
  scsi: core: Run queue in case of I/O resource contention failure

Author: torvalds

drivers/scsi/scsi_lib.c

@@ -547,6 +547,15 @@ static void scsi_mq_uninit_cmd(struct scsi_cmnd *cmd)
 	scsi_uninit_cmd(cmd);
 }
 
+static void scsi_run_queue_async(struct scsi_device *sdev)
+{
+	if (scsi_target(sdev)->single_lun ||
+	    !list_empty(&sdev->host->starved_list))
+		kblockd_schedule_work(&sdev->requeue_work);
+	else
+		blk_mq_run_hw_queues(sdev->request_queue, true);
+}
+
 /* Returns false when no more bytes to process, true if there are more */
 static bool scsi_end_request(struct request *req, blk_status_t error,
 		unsigned int bytes)
@@ -591,11 +600,7 @@ static bool scsi_end_request(struct request *req, blk_status_t error,
 
 	__blk_mq_end_request(req, error);
 
-	if (scsi_target(sdev)->single_lun ||
-	    !list_empty(&sdev->host->starved_list))
-		kblockd_schedule_work(&sdev->requeue_work);
-	else
-		blk_mq_run_hw_queues(q, true);
+	scsi_run_queue_async(sdev);
 
 	percpu_ref_put(&q->q_usage_counter);
 	return false;
@@ -1702,6 +1707,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 		 */
 		if (req->rq_flags & RQF_DONTPREP)
 			scsi_mq_uninit_cmd(cmd);
+		scsi_run_queue_async(sdev);
 		break;
 	}
 	return ret;