[SCSI] scsi_transport_sas: add expander backlink
This patch adds the ability to add a backlink to a particular port. The
idea is to represent properly ports on expanders that are used
specifically for linking to the parent device in the topology.
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index 9bb4e37..7871bc2 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -692,6 +692,13 @@
}
mutex_unlock(&port->phy_list_mutex);
+ if (port->is_backlink) {
+ struct device *parent = port->dev.parent;
+
+ sysfs_remove_link(&port->dev.kobj, parent->bus_id);
+ port->is_backlink = 0;
+ }
+
transport_remove_device(dev);
device_del(dev);
transport_destroy_device(dev);
@@ -767,6 +774,19 @@
}
EXPORT_SYMBOL(sas_port_delete_phy);
+void sas_port_mark_backlink(struct sas_port *port)
+{
+ struct device *parent = port->dev.parent->parent->parent;
+
+ if (port->is_backlink)
+ return;
+ port->is_backlink = 1;
+ sysfs_create_link(&port->dev.kobj, &parent->kobj,
+ parent->bus_id);
+
+}
+EXPORT_SYMBOL(sas_port_mark_backlink);
+
/*
* SAS remote PHY attributes.
*/
diff --git a/include/scsi/scsi_transport_sas.h b/include/scsi/scsi_transport_sas.h
index f5772ff..6cc2314 100644
--- a/include/scsi/scsi_transport_sas.h
+++ b/include/scsi/scsi_transport_sas.h
@@ -130,6 +130,8 @@
int port_identifier;
int num_phys;
+ /* port flags */
+ unsigned int is_backlink:1;
/* the other end of the link */
struct sas_rphy *rphy;
@@ -175,6 +177,7 @@
void sas_port_delete(struct sas_port *);
void sas_port_add_phy(struct sas_port *, struct sas_phy *);
void sas_port_delete_phy(struct sas_port *, struct sas_phy *);
+void sas_port_mark_backlink(struct sas_port *);
int scsi_is_sas_port(const struct device *);
extern struct scsi_transport_template *