[PATCH 4.2.y-ckt 096/273] scsi_dh_rdac: always retry MODE SELECT on command lock violation

From: Kamal Mostafa
Date: Mon Mar 07 2016 - 19:33:18 EST


4.2.8-ckt5 -stable review patch. If anyone has any objections, please let me know.

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

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: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
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 b46ace3..dd0c133a 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -568,7 +568,7 @@ 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;
@@ -618,6 +618,8 @@ 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;
--
2.7.0