[SCSI] iscsi class: sysfs group is_visible callout for iscsi host attrs

The iscsi class currently does not support writable sysfs
attrs for LLD sysfs settings. This patch converts the
iscsi class and driver's host attrs to use the attribute
container sysfs group and the sysfs group's is_visible callout
to be able to support readable or writable sysfs attrs.

Signed-off-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 38 insertions, 20 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index a8dd85dc77b..2e9b6821559 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -32,8 +32,6 @@
 #include <scsi/iscsi_if.h>
 #include <scsi/scsi_cmnd.h>
 
-#define ISCSI_HOST_ATTRS 4
-
 #define ISCSI_TRANSPORT_VERSION "2.0-870"
 
 static int dbg_session;
@@ -74,7 +72,6 @@ struct iscsi_internal {
 	struct list_head list;
 	struct device dev;
 
-	struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
 	struct transport_container conn_cont;
 	struct transport_container session_cont;
 };
@@ -2301,13 +2298,42 @@ iscsi_host_attr(hwaddress, ISCSI_HOST_PARAM_HWADDRESS);
 iscsi_host_attr(ipaddress, ISCSI_HOST_PARAM_IPADDRESS);
 iscsi_host_attr(initiatorname, ISCSI_HOST_PARAM_INITIATOR_NAME);
 
-#define SETUP_HOST_RD_ATTR(field, param_flag)				\
-do {									\
-	if (tt->host_param_mask & param_flag) {				\
-		priv->host_attrs[count] = &dev_attr_host_##field; \
-		count++;						\
-	}								\
-} while (0)
+static struct attribute *iscsi_host_attrs[] = {
+	&dev_attr_host_netdev.attr,
+	&dev_attr_host_hwaddress.attr,
+	&dev_attr_host_ipaddress.attr,
+	&dev_attr_host_initiatorname.attr,
+	NULL,
+};
+
+static mode_t iscsi_host_attr_is_visible(struct kobject *kobj,
+					 struct attribute *attr, int i)
+{
+	struct device *cdev = container_of(kobj, struct device, kobj);
+	struct Scsi_Host *shost = transport_class_to_shost(cdev);
+	struct iscsi_internal *priv = to_iscsi_internal(shost->transportt);
+	int param;
+
+	if (attr == &dev_attr_host_netdev.attr)
+		param = ISCSI_HOST_PARAM_NETDEV_NAME;
+	else if (attr == &dev_attr_host_hwaddress.attr)
+		param = ISCSI_HOST_PARAM_HWADDRESS;
+	else if (attr == &dev_attr_host_ipaddress.attr)
+		param = ISCSI_HOST_PARAM_IPADDRESS;
+	else if (attr == &dev_attr_host_initiatorname.attr)
+		param = ISCSI_HOST_PARAM_INITIATOR_NAME;
+	else {
+		WARN_ONCE(1, "Invalid host attr");
+		return 0;
+	}
+
+	return priv->iscsi_transport->attr_is_visible(ISCSI_HOST_PARAM, param);
+}
+
+static struct attribute_group iscsi_host_group = {
+	.attrs = iscsi_host_attrs,
+	.is_visible = iscsi_host_attr_is_visible,
+};
 
 static int iscsi_session_match(struct attribute_container *cont,
 			   struct device *dev)
@@ -2379,7 +2405,7 @@ iscsi_register_transport(struct iscsi_transport *tt)
 {
 	struct iscsi_internal *priv;
 	unsigned long flags;
-	int count = 0, err;
+	int err;
 
 	BUG_ON(!tt);
 
@@ -2406,20 +2432,12 @@ iscsi_register_transport(struct iscsi_transport *tt)
 		goto unregister_dev;
 
 	/* host parameters */
-	priv->t.host_attrs.ac.attrs = &priv->host_attrs[0];
 	priv->t.host_attrs.ac.class = &iscsi_host_class.class;
 	priv->t.host_attrs.ac.match = iscsi_host_match;
+	priv->t.host_attrs.ac.grp = &iscsi_host_group;
 	priv->t.host_size = sizeof(struct iscsi_cls_host);
 	transport_container_register(&priv->t.host_attrs);
 
-	SETUP_HOST_RD_ATTR(netdev, ISCSI_HOST_NETDEV_NAME);
-	SETUP_HOST_RD_ATTR(ipaddress, ISCSI_HOST_IPADDRESS);
-	SETUP_HOST_RD_ATTR(hwaddress, ISCSI_HOST_HWADDRESS);
-	SETUP_HOST_RD_ATTR(initiatorname, ISCSI_HOST_INITIATOR_NAME);
-	BUG_ON(count > ISCSI_HOST_ATTRS);
-	priv->host_attrs[count] = NULL;
-	count = 0;
-
 	/* connection parameters */
 	priv->conn_cont.ac.class = &iscsi_connection_class.class;
 	priv->conn_cont.ac.match = iscsi_conn_match;