[PATCH 4.4 039/137] scsi_dh_rdac: always retry MODE SELECT on command lock violation

From: Greg Kroah-Hartman
Date: Tue Feb 23 2016 - 23:48:45 EST


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

------------------

From: Hannes Reinecke <hare@xxxxxxx>

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 <hare@xxxxxxx>
Reviewed-by: Johannes Thumshirn <jthumshirn@xxxxxxx>
Signed-off-by: Martin K. Petersen <martin.petersen@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
drivers/scsi/device_handler/scsi_dh_rdac.c | 4 +++-
1 file changed, 3 insertions(+), 1 deletion(-)

--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -562,7 +562,7 @@ static int mode_select_handle_sense(stru
/*
* Command Lock contention
*/
- err = SCSI_DH_RETRY;
+ err = SCSI_DH_IMM_RETRY;
break;
default:
break;
@@ -612,6 +612,8 @@ 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;