[SCSI] iscsi cls: sysfs group is_visible callout for conn attrs

The iscsi class currently does not support writable sysfs
attrs for LLD sysfs settings. This patch converts the
iscsi class and drivers 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, 65 insertions, 28 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index 4d5e64f429e7..e9eca98e1102 100644
--- a/drivers/scsi/scsi_transport_iscsi.c
+++ b/drivers/scsi/scsi_transport_iscsi.c
@@ -78,7 +78,6 @@ struct iscsi_internal {
 
         struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
         struct transport_container conn_cont;
-        struct device_attribute *conn_attrs[ISCSI_CONN_ATTRS + 1];
         struct transport_container session_cont;
         struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
 };
@@ -2030,6 +2029,70 @@ static ISCSI_CLASS_ATTR(conn, field, S_IRUGO,				\
 iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
 iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);
 
+static struct attribute *iscsi_conn_attrs[] = {
+        &dev_attr_conn_max_recv_dlength.attr,
+        &dev_attr_conn_max_xmit_dlength.attr,
+        &dev_attr_conn_header_digest.attr,
+        &dev_attr_conn_data_digest.attr,
+        &dev_attr_conn_ifmarker.attr,
+        &dev_attr_conn_ofmarker.attr,
+        &dev_attr_conn_address.attr,
+        &dev_attr_conn_port.attr,
+        &dev_attr_conn_exp_statsn.attr,
+        &dev_attr_conn_persistent_address.attr,
+        &dev_attr_conn_persistent_port.attr,
+        &dev_attr_conn_ping_tmo.attr,
+        &dev_attr_conn_recv_tmo.attr,
+        NULL,
+};
+
+static mode_t iscsi_conn_attr_is_visible(struct kobject *kobj,
+                                         struct attribute *attr, int i)
+{
+        struct device *cdev = container_of(kobj, struct device, kobj);
+        struct iscsi_cls_conn *conn = transport_class_to_conn(cdev);
+        struct iscsi_transport *t = conn->transport;
+        int param;
+
+        if (attr == &dev_attr_conn_max_recv_dlength.attr)
+                param = ISCSI_PARAM_MAX_RECV_DLENGTH;
+        else if (attr == &dev_attr_conn_max_xmit_dlength.attr)
+                param = ISCSI_PARAM_MAX_XMIT_DLENGTH;
+        else if (attr == &dev_attr_conn_header_digest.attr)
+                param = ISCSI_PARAM_HDRDGST_EN;
+        else if (attr == &dev_attr_conn_data_digest.attr)
+                param = ISCSI_PARAM_DATADGST_EN;
+        else if (attr == &dev_attr_conn_ifmarker.attr)
+                param = ISCSI_PARAM_IFMARKER_EN;
+        else if (attr == &dev_attr_conn_ofmarker.attr)
+                param = ISCSI_PARAM_OFMARKER_EN;
+        else if (attr == &dev_attr_conn_address.attr)
+                param = ISCSI_PARAM_CONN_ADDRESS;
+        else if (attr == &dev_attr_conn_port.attr)
+                param = ISCSI_PARAM_CONN_PORT;
+        else if (attr == &dev_attr_conn_exp_statsn.attr)
+                param = ISCSI_PARAM_EXP_STATSN;
+        else if (attr == &dev_attr_conn_persistent_address.attr)
+                param = ISCSI_PARAM_PERSISTENT_ADDRESS;
+        else if (attr == &dev_attr_conn_persistent_port.attr)
+                param = ISCSI_PARAM_PERSISTENT_PORT;
+        else if (attr == &dev_attr_conn_ping_tmo.attr)
+                param = ISCSI_PARAM_PING_TMO;
+        else if (attr == &dev_attr_conn_recv_tmo.attr)
+                param = ISCSI_PARAM_RECV_TMO;
+        else {
+                WARN_ONCE(1, "Invalid conn attr");
+                return 0;
+        }
+
+        return t->attr_is_visible(ISCSI_PARAM, param);
+}
+
+static struct attribute_group iscsi_conn_group = {
+        .attrs = iscsi_conn_attrs,
+        .is_visible = iscsi_conn_attr_is_visible,
+};
+
 /*
  * iSCSI session attrs
  */
@@ -2171,14 +2234,6 @@ do {									\
         }                                                               \
 } while (0)
 
-#define SETUP_CONN_RD_ATTR(field, param_flag)                           \
-do {                                                                    \
-        if (tt->param_mask & param_flag) {                              \
-                priv->conn_attrs[count] = &dev_attr_conn_##field; \
-                count++;                                                \
-        }                                                               \
-} while (0)
-
 #define SETUP_HOST_RD_ATTR(field, param_flag)                           \
 do {                                                                    \
         if (tt->host_param_mask & param_flag) {                         \
@@ -2299,29 +2354,11 @@ iscsi_register_transport(struct iscsi_transport *tt)
         count = 0;
 
         /* connection parameters */
-        priv->conn_cont.ac.attrs = &priv->conn_attrs[0];
         priv->conn_cont.ac.class = &iscsi_connection_class.class;
         priv->conn_cont.ac.match = iscsi_conn_match;
+        priv->conn_cont.ac.grp = &iscsi_conn_group;
         transport_container_register(&priv->conn_cont);
 
-        SETUP_CONN_RD_ATTR(max_recv_dlength, ISCSI_MAX_RECV_DLENGTH);
-        SETUP_CONN_RD_ATTR(max_xmit_dlength, ISCSI_MAX_XMIT_DLENGTH);
-        SETUP_CONN_RD_ATTR(header_digest, ISCSI_HDRDGST_EN);
-        SETUP_CONN_RD_ATTR(data_digest, ISCSI_DATADGST_EN);
-        SETUP_CONN_RD_ATTR(ifmarker, ISCSI_IFMARKER_EN);
-        SETUP_CONN_RD_ATTR(ofmarker, ISCSI_OFMARKER_EN);
-        SETUP_CONN_RD_ATTR(address, ISCSI_CONN_ADDRESS);
-        SETUP_CONN_RD_ATTR(port, ISCSI_CONN_PORT);
-        SETUP_CONN_RD_ATTR(exp_statsn, ISCSI_EXP_STATSN);
-        SETUP_CONN_RD_ATTR(persistent_address, ISCSI_PERSISTENT_ADDRESS);
-        SETUP_CONN_RD_ATTR(persistent_port, ISCSI_PERSISTENT_PORT);
-        SETUP_CONN_RD_ATTR(ping_tmo, ISCSI_PING_TMO);
-        SETUP_CONN_RD_ATTR(recv_tmo, ISCSI_RECV_TMO);
-
-        BUG_ON(count > ISCSI_CONN_ATTRS);
-        priv->conn_attrs[count] = NULL;
-        count = 0;
-
         /* session parameters */
         priv->session_cont.ac.attrs = &priv->session_attrs[0];
         priv->session_cont.ac.class = &iscsi_session_class.class;