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

The iscsi class currently does not support writable sysfs
attrs for LLD sysfs settings. This patch converts the
iscsi class and driver's session 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, 95 insertions, 53 deletions

diff --git a/drivers/scsi/scsi_transport_iscsi.c b/drivers/scsi/scsi_transport_iscsi.c
index e9eca98e110..75d7f6e93b6 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_SESSION_ATTRS 23
-#define ISCSI_CONN_ATTRS 13
 #define ISCSI_HOST_ATTRS 4
 
 #define ISCSI_TRANSPORT_VERSION "2.0-870"
@@ -79,7 +77,6 @@ struct iscsi_internal {
 	struct device_attribute *host_attrs[ISCSI_HOST_ATTRS + 1];
 	struct transport_container conn_cont;
 	struct transport_container session_cont;
-	struct device_attribute *session_attrs[ISCSI_SESSION_ATTRS + 1];
 };
 
 static atomic_t iscsi_session_nr; /* sysfs session id for next new session */
@@ -2114,7 +2111,6 @@ show_session_param_##param(struct device *dev,				\
 	iscsi_session_attr_show(param, perm)				\
 static ISCSI_CLASS_ATTR(sess, field, S_IRUGO, show_session_param_##param, \
 			NULL);
-
 iscsi_session_attr(targetname, ISCSI_PARAM_TARGET_NAME, 0);
 iscsi_session_attr(initial_r2t, ISCSI_PARAM_INITIAL_R2T_EN, 0);
 iscsi_session_attr(max_outstanding_r2t, ISCSI_PARAM_MAX_R2T, 0);
@@ -2191,6 +2187,100 @@ static ISCSI_CLASS_ATTR(priv_sess, field, S_IRUGO | S_IWUSR,		\
 			store_priv_session_##field)
 iscsi_priv_session_rw_attr(recovery_tmo, "%d");
 
+static struct attribute *iscsi_session_attrs[] = {
+	&dev_attr_sess_initial_r2t.attr,
+	&dev_attr_sess_max_outstanding_r2t.attr,
+	&dev_attr_sess_immediate_data.attr,
+	&dev_attr_sess_first_burst_len.attr,
+	&dev_attr_sess_max_burst_len.attr,
+	&dev_attr_sess_data_pdu_in_order.attr,
+	&dev_attr_sess_data_seq_in_order.attr,
+	&dev_attr_sess_erl.attr,
+	&dev_attr_sess_targetname.attr,
+	&dev_attr_sess_tpgt.attr,
+	&dev_attr_sess_password.attr,
+	&dev_attr_sess_password_in.attr,
+	&dev_attr_sess_username.attr,
+	&dev_attr_sess_username_in.attr,
+	&dev_attr_sess_fast_abort.attr,
+	&dev_attr_sess_abort_tmo.attr,
+	&dev_attr_sess_lu_reset_tmo.attr,
+	&dev_attr_sess_tgt_reset_tmo.attr,
+	&dev_attr_sess_ifacename.attr,
+	&dev_attr_sess_initiatorname.attr,
+	&dev_attr_sess_targetalias.attr,
+	&dev_attr_priv_sess_recovery_tmo.attr,
+	&dev_attr_priv_sess_state.attr,
+	NULL,
+};
+
+static mode_t iscsi_session_attr_is_visible(struct kobject *kobj,
+					    struct attribute *attr, int i)
+{
+	struct device *cdev = container_of(kobj, struct device, kobj);
+	struct iscsi_cls_session *session = transport_class_to_session(cdev);
+	struct iscsi_transport *t = session->transport;
+	int param;
+
+	if (attr == &dev_attr_sess_initial_r2t.attr)
+		param = ISCSI_PARAM_INITIAL_R2T_EN;
+	else if (attr == &dev_attr_sess_max_outstanding_r2t.attr)
+		param = ISCSI_PARAM_MAX_R2T;
+	else if (attr == &dev_attr_sess_immediate_data.attr)
+		param = ISCSI_PARAM_IMM_DATA_EN;
+	else if (attr == &dev_attr_sess_first_burst_len.attr)
+		param = ISCSI_PARAM_FIRST_BURST;
+	else if (attr == &dev_attr_sess_max_burst_len.attr)
+		param = ISCSI_PARAM_MAX_BURST;
+	else if (attr == &dev_attr_sess_data_pdu_in_order.attr)
+		param = ISCSI_PARAM_PDU_INORDER_EN;
+	else if (attr == &dev_attr_sess_data_seq_in_order.attr)
+		param = ISCSI_PARAM_DATASEQ_INORDER_EN;
+	else if (attr == &dev_attr_sess_erl.attr)
+		param = ISCSI_PARAM_ERL;
+	else if (attr == &dev_attr_sess_targetname.attr)
+		param = ISCSI_PARAM_TARGET_NAME;
+	else if (attr == &dev_attr_sess_tpgt.attr)
+		param = ISCSI_PARAM_TPGT;
+	else if (attr == &dev_attr_sess_password.attr)
+		param = ISCSI_PARAM_USERNAME;
+	else if (attr == &dev_attr_sess_password_in.attr)
+		param = ISCSI_PARAM_USERNAME_IN;
+	else if (attr == &dev_attr_sess_username.attr)
+		param = ISCSI_PARAM_PASSWORD;
+	else if (attr == &dev_attr_sess_username_in.attr)
+		param = ISCSI_PARAM_PASSWORD_IN;
+	else if (attr == &dev_attr_sess_fast_abort.attr)
+		param = ISCSI_PARAM_FAST_ABORT;
+	else if (attr == &dev_attr_sess_abort_tmo.attr)
+		param = ISCSI_PARAM_ABORT_TMO;
+	else if (attr == &dev_attr_sess_lu_reset_tmo.attr)
+		param = ISCSI_PARAM_LU_RESET_TMO;
+	else if (attr == &dev_attr_sess_tgt_reset_tmo.attr)
+		param = ISCSI_PARAM_TGT_RESET_TMO;
+	else if (attr == &dev_attr_sess_ifacename.attr)
+		param = ISCSI_PARAM_IFACE_NAME;
+	else if (attr == &dev_attr_sess_initiatorname.attr)
+		param = ISCSI_PARAM_INITIATOR_NAME;
+	else if (attr == &dev_attr_sess_targetalias.attr)
+		param = ISCSI_PARAM_TARGET_ALIAS;
+	else if (attr == &dev_attr_priv_sess_recovery_tmo.attr)
+		return S_IRUGO | S_IWUSR;
+	else if (attr == &dev_attr_priv_sess_state.attr)
+		return S_IRUGO;
+	else {
+		WARN_ONCE(1, "Invalid session attr");
+		return 0;
+	}
+
+	return t->attr_is_visible(ISCSI_PARAM, param);
+}
+
+static struct attribute_group iscsi_session_group = {
+	.attrs = iscsi_session_attrs,
+	.is_visible = iscsi_session_attr_is_visible,
+};
+
 /*
  * iSCSI host attrs
  */
@@ -2214,26 +2304,6 @@ 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_PRIV_SESSION_RD_ATTR(field)				\
-do {									\
-	priv->session_attrs[count] = &dev_attr_priv_sess_##field; \
-	count++;							\
-} while (0)
-
-#define SETUP_PRIV_SESSION_RW_ATTR(field)				\
-do {									\
-	priv->session_attrs[count] = &dev_attr_priv_sess_##field;	\
-	count++;							\
-} while (0)
-
-#define SETUP_SESSION_RD_ATTR(field, param_flag)			\
-do {									\
-	if (tt->param_mask & param_flag) {				\
-		priv->session_attrs[count] = &dev_attr_sess_##field; \
-		count++;						\
-	}								\
-} while (0)
-
 #define SETUP_HOST_RD_ATTR(field, param_flag)				\
 do {									\
 	if (tt->host_param_mask & param_flag) {				\
@@ -2360,39 +2430,11 @@ iscsi_register_transport(struct iscsi_transport *tt)
 	transport_container_register(&priv->conn_cont);
 
 	/* session parameters */
-	priv->session_cont.ac.attrs = &priv->session_attrs[0];
 	priv->session_cont.ac.class = &iscsi_session_class.class;
 	priv->session_cont.ac.match = iscsi_session_match;
+	priv->session_cont.ac.grp = &iscsi_session_group;
 	transport_container_register(&priv->session_cont);
 
-	SETUP_SESSION_RD_ATTR(initial_r2t, ISCSI_INITIAL_R2T_EN);
-	SETUP_SESSION_RD_ATTR(max_outstanding_r2t, ISCSI_MAX_R2T);
-	SETUP_SESSION_RD_ATTR(immediate_data, ISCSI_IMM_DATA_EN);
-	SETUP_SESSION_RD_ATTR(first_burst_len, ISCSI_FIRST_BURST);
-	SETUP_SESSION_RD_ATTR(max_burst_len, ISCSI_MAX_BURST);
-	SETUP_SESSION_RD_ATTR(data_pdu_in_order, ISCSI_PDU_INORDER_EN);
-	SETUP_SESSION_RD_ATTR(data_seq_in_order, ISCSI_DATASEQ_INORDER_EN);
-	SETUP_SESSION_RD_ATTR(erl, ISCSI_ERL);
-	SETUP_SESSION_RD_ATTR(targetname, ISCSI_TARGET_NAME);
-	SETUP_SESSION_RD_ATTR(tpgt, ISCSI_TPGT);
-	SETUP_SESSION_RD_ATTR(password, ISCSI_USERNAME);
-	SETUP_SESSION_RD_ATTR(password_in, ISCSI_USERNAME_IN);
-	SETUP_SESSION_RD_ATTR(username, ISCSI_PASSWORD);
-	SETUP_SESSION_RD_ATTR(username_in, ISCSI_PASSWORD_IN);
-	SETUP_SESSION_RD_ATTR(fast_abort, ISCSI_FAST_ABORT);
-	SETUP_SESSION_RD_ATTR(abort_tmo, ISCSI_ABORT_TMO);
-	SETUP_SESSION_RD_ATTR(lu_reset_tmo,ISCSI_LU_RESET_TMO);
-	SETUP_SESSION_RD_ATTR(tgt_reset_tmo,ISCSI_TGT_RESET_TMO);
-	SETUP_SESSION_RD_ATTR(ifacename, ISCSI_IFACE_NAME);
-	SETUP_SESSION_RD_ATTR(initiatorname, ISCSI_INITIATOR_NAME);
-	SETUP_SESSION_RD_ATTR(targetalias, ISCSI_TARGET_ALIAS);
-	SETUP_PRIV_SESSION_RW_ATTR(recovery_tmo);
-	SETUP_PRIV_SESSION_RD_ATTR(state);
-
-	BUG_ON(count > ISCSI_SESSION_ATTRS);
-	priv->session_attrs[count] = NULL;
-	count = 0;
-
 	spin_lock_irqsave(&iscsi_transport_lock, flags);
 	list_add(&priv->list, &iscsi_transports);
 	spin_unlock_irqrestore(&iscsi_transport_lock, flags);