scsi_dh_alua: move optimize_stpg evaluation

When the optimize_stpg module option is set we should just set it
once during port_group allocation. Doing so allows us to override
it later with device specific settings.
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

BugLink: http://bugs.launchpad.net/bugs/1567602

(cherry-picked from commit aa90f490)
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>
Acked-by: Brad Figg <brad.figg@canonical.com>
Signed-off-by: Kamal Mostafa <kamal@canonical.com>

drivers/scsi/device_handler/scsi_dh_alua.c

@@ -64,6 +64,10 @@
 #define ALUA_OPTIMIZE_STPG		1
 #define ALUA_RTPG_EXT_HDR_UNSUPP	2
 
+static uint optimize_stpg;
+module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR);
+MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0.");
+
 static LIST_HEAD(port_group_list);
 static DEFINE_SPINLOCK(port_group_lock);
 
@@ -219,6 +223,8 @@ struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev,
 	pg->group_id = group_id;
 	pg->tpgs = tpgs;
 	pg->state = TPGS_STATE_OPTIMIZED;
+	if (optimize_stpg)
+		pg->flags |= ALUA_OPTIMIZE_STPG;
 	kref_init(&pg->kref);
 
 	spin_lock(&port_group_lock);
@@ -678,10 +684,6 @@ static int alua_set_params(struct scsi_device *sdev, const char *params)
 	return result;
 }
 
-static uint optimize_stpg;
-module_param(optimize_stpg, uint, S_IRUGO|S_IWUSR);
-MODULE_PARM_DESC(optimize_stpg, "Allow use of a non-optimized path, rather than sending a STPG, when implicit TPGS is supported (0=No,1=Yes). Default is 0.");
-
 /*
  * alua_activate - activate a path
  * @sdev: device on the path to be activated
@@ -703,9 +705,6 @@ static int alua_activate(struct scsi_device *sdev,
 
 	kref_get(&h->pg->kref);
 
-	if (optimize_stpg)
-		h->pg->flags |= ALUA_OPTIMIZE_STPG;
-
 	err = alua_rtpg(sdev, h->pg);
 	if (err != SCSI_DH_OK) {
 		kref_put(&h->pg->kref, release_port_group);