[PATCH 3.16.y-ckt 092/129] scsi_dh_rdac: always retry MODE SELECT on command lock violation

[Luis Henriques]

3.16.7-ckt25 -stable review patch.  If anyone has any objections, please let me 
know.

---8<------------------------------------------------------------

From: Hannes Reinecke <h...@suse.de>

commit d2d06d4fe0f2cc2df9b17fefec96e6e1a1271d91 upstream.

If MODE SELECT returns with sense '05/91/36' (command lock violation)
it should always be retried without counting the number of retries.
During an HBA upgrade or similar circumstances one might see a flood
of MODE SELECT command from various HBAs, which will easily trigger
the sense code and exceed the retry count.

Signed-off-by: Hannes Reinecke <h...@suse.de>
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
Signed-off-by: Martin K. Petersen <martin.peter...@oracle.com>
Signed-off-by: Luis Henriques <luis.henriq...@canonical.com>
---
 drivers/scsi/device_handler/scsi_dh_rdac.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c 
b/drivers/scsi/device_handler/scsi_dh_rdac.c
index 826069db9848..350c2623a50f 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -569,7 +569,7 @@ static int mode_select_handle_sense(struct scsi_device 
*sdev,
                        /*
                         * Command Lock contention
                         */
-                       err = SCSI_DH_RETRY;
+                       err = SCSI_DH_IMM_RETRY;
                break;
        default:
                break;
@@ -619,6 +619,8 @@ retry:
                err = mode_select_handle_sense(sdev, h->sense);
                if (err == SCSI_DH_RETRY && retry_cnt--)
                        goto retry;
+               if (err == SCSI_DH_IMM_RETRY)
+                       goto retry;
        }
        if (err == SCSI_DH_OK) {
                h->state = RDAC_STATE_ACTIVE;