[SCSI] Fix dm-multipath starvation when scsi host is busy

[android-x86/kernel.git] / drivers / scsi / scsi_lib.c

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 62ddfd3..6dfb978 100644 (file)
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1378,16 +1378,19 @@ static int scsi_lld_busy(struct request_queue *q)
 {
        struct scsi_device *sdev = q->queuedata;
        struct Scsi_Host *shost;
-       struct scsi_target *starget;
 
        if (!sdev)
                return 0;
 
        shost = sdev->host;
-       starget = scsi_target(sdev);
 
-       if (scsi_host_in_recovery(shost) || scsi_host_is_busy(shost) ||
-           scsi_target_is_busy(starget) || scsi_device_is_busy(sdev))
+       /*
+        * Ignore host/starget busy state.
+        * Since block layer does not have a concept of fairness across
+        * multiple queues, congestion of host/starget needs to be handled
+        * in SCSI layer.
+        */
+       if (scsi_host_in_recovery(shost) || scsi_device_is_busy(sdev))
                return 1;
 
        return 0;