Patch "scsi_dh_rdac: always retry MODE SELECT on command lock violation" has been added to the 4.4-stable tree

[<gregkh@linuxfoundation.org>]

This is a note to let you know that I've just added the patch titled

    scsi_dh_rdac: always retry MODE SELECT on command lock violation

to the 4.4-stable tree which can be found at:
    http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
     scsi_dh_rdac-always-retry-mode-select-on-command-lock-violation.patch
and it can be found in the queue-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From d2d06d4fe0f2cc2df9b17fefec96e6e1a1271d91 Mon Sep 17 00:00:00 2001
From: Hannes Reinecke <hare@suse.de>
Date: Fri, 22 Jan 2016 15:42:41 +0100
Subject: scsi_dh_rdac: always retry MODE SELECT on command lock violation

From: Hannes Reinecke <hare@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 <hare@suse.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 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;


Patches currently in stable-queue which might be from hare@suse.de are

queue-4.4/modules-fix-modparam-async_probe-request.patch
queue-4.4/scsi_dh_rdac-always-retry-mode-select-on-command-lock-violation.patch
queue-4.4/iscsi-target-fix-potential-dead-lock-during-node-acl-delete.patch