[RFC v1 6/8] scsi: Add multipath suppport for device handler

[himanshu.madhani@xxxxxxxxxx]

From: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>

Add multipath initialization during handler attachemnet for DH.
Also initialize multipath port group data for scsi_device.

Signed-off-by: Himanshu Madhani <himanshu.madhani@xxxxxxxxxx>
---
 drivers/scsi/device_handler/scsi_dh_alua.c | 15 +++++++++++++++
 drivers/scsi/scsi_dh.c                     |  3 +++
 2 files changed, 18 insertions(+)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 4eb0837298d4..29bd6517a2e3 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -258,6 +258,21 @@ static struct alua_port_group *alua_alloc_pg(struct scsi_device *sdev,
 		return tmp_pg;
 	}
 
+	if (scsi_mpath_enabled(sdev)) {
+		struct scsi_mpath_dh_data *dh_data = sdev->mpath_pg_data;
+
+		dh_data->group_id = pg->group_id;
+		dh_data->tpgs = pg->tpgs;
+		dh_data->state = pg->state;
+		dh_data->valid_states = pg->valid_states;
+		dh_data->prefrence = pg->pref;
+		dh_data->is_active = 1;
+		dh_data->device_id_str = kstrdup(pg->device_id_str, GFP_KERNEL);
+		dh_data->device_id_len = pg->device_id_len;
+
+		sdev->host->mpath_alua_grpid = pg->group_id;
+	}
+
 	list_add(&pg->node, &port_group_list);
 	spin_unlock(&port_group_lock);
 
diff --git a/drivers/scsi/scsi_dh.c b/drivers/scsi/scsi_dh.c
index 7b56e00c7df6..d61eddc3c1f8 100644
--- a/drivers/scsi/scsi_dh.c
+++ b/drivers/scsi/scsi_dh.c
@@ -129,6 +129,9 @@ static int scsi_dh_handler_attach(struct scsi_device *sdev,
 	if (!try_module_get(scsi_dh->module))
 		return -EINVAL;
 
+	if (scsi_mpath_enabled(sdev))
+		scsi_multipath_init(sdev);
+
 	error = scsi_dh->attach(sdev);
 	if (error != SCSI_DH_OK) {
 		switch (error) {
-- 
2.41.0.rc2