[SCSI] iscsi class: add callout to get iscsi_endpoint values

For drivers using the ep callbacks the addr and port are attached to the endpoint instead of the conn. This adds a callout to the iscsi_transport to get ep values. It also adds locking around the get param call to make sure that ep_disconnect does not free the LLD's ep interconnect structs from under us (the ep has a refcount so it will not go away but the LLD may have structs from other subsystems that are not allocated in the ep so we need to protect them from getting freed). Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@suse.de>

[SCSI] iscsi class: add callout to get iscsi_endpoint values
For drivers using the ep callbacks the addr and port are attached to the endpoint instead of the conn. This adds a callout to the iscsi_transport to get ep values. It also adds locking around the get param call to make sure that ep_disconnect does not free the LLD's ep interconnect structs from under us (the ep has a refcount so it will not go away but the LLD may have structs from other subsystems that are not allocated in the ep so we need to protect them from getting freed). Signed-off-by: Mike Christie <michaelc@cs.wisc.edu> Signed-off-by: James Bottomley <James.Bottomley@suse.de>
Mike Christie · James Bottomley
1 parent a79af8a64d
Showing 2 changed files with 39 additions and 2 deletions Side-by-side Diff
drivers/scsi/scsi_transport_iscsi.c
include/scsi/scsi_transport_iscsi.h
@@ -1782,12 +1782,47 @@
 iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
 iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
 iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
-iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
 iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
 iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
-iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
 iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
 iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
+
+#define iscsi_conn_ep_attr_show(param)					\
+static ssize_t show_conn_ep_param_##param(struct device *dev,		\
+					  struct device_attribute *attr,\
+					  char *buf)			\
+{									\
+	struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent);	\
+	struct iscsi_transport *t = conn->transport;			\
+	struct iscsi_endpoint *ep;					\
+	ssize_t rc;							\
+									\
+	/*								\
+	 * Need to make sure ep_disconnect does not free the LLD's	\
+	 * interconnect resources while we are trying to read them.	\
+	 */								\
+	mutex_lock(&conn->ep_mutex);					\
+	ep = conn->ep;							\
+	if (!ep && t->ep_connect) {					\
+		mutex_unlock(&conn->ep_mutex);				\
+		return -ENOTCONN;					\
+	}								\
+									\
+	if (ep)								\
+		rc = t->get_ep_param(ep, param, buf);			\
+	else								\
+		rc = t->get_conn_param(conn, param, buf);		\
+	mutex_unlock(&conn->ep_mutex);					\
+	return rc;							\
+}
+
+#define iscsi_conn_ep_attr(field, param)				\
+	iscsi_conn_ep_attr_show(param)					\
+static ISCSI_CLASS_ATTR(conn, field, S_IRUGO,				\
+			show_conn_ep_param_##param, NULL);
+
+iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
+iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);
  
 /*
  * iSCSI session attrs
@@ -101,6 +101,8 @@
 	void (*destroy_conn) (struct iscsi_cls_conn *conn);
 	int (*set_param) (struct iscsi_cls_conn *conn, enum iscsi_param param,
 			  char *buf, int buflen);
+	int (*get_ep_param) (struct iscsi_endpoint *ep, enum iscsi_param param,
+			     char *buf);
 	int (*get_conn_param) (struct iscsi_cls_conn *conn,
 			       enum iscsi_param param, char *buf);
 	int (*get_session_param) (struct iscsi_cls_session *session,
...	...	@@ -1782,12 +1782,47 @@
1782	1782	iscsi_conn_attr(ifmarker, ISCSI_PARAM_IFMARKER_EN);
1783	1783	iscsi_conn_attr(ofmarker, ISCSI_PARAM_OFMARKER_EN);
1784	1784	iscsi_conn_attr(persistent_port, ISCSI_PARAM_PERSISTENT_PORT);
1785		-iscsi_conn_attr(port, ISCSI_PARAM_CONN_PORT);
1786	1785	iscsi_conn_attr(exp_statsn, ISCSI_PARAM_EXP_STATSN);
1787	1786	iscsi_conn_attr(persistent_address, ISCSI_PARAM_PERSISTENT_ADDRESS);
1788		-iscsi_conn_attr(address, ISCSI_PARAM_CONN_ADDRESS);
1789	1787	iscsi_conn_attr(ping_tmo, ISCSI_PARAM_PING_TMO);
1790	1788	iscsi_conn_attr(recv_tmo, ISCSI_PARAM_RECV_TMO);
	1789	+
	1790	+#define iscsi_conn_ep_attr_show(param) \
	1791	+static ssize_t show_conn_ep_param_##param(struct device *dev, \
	1792	+ struct device_attribute *attr,\
	1793	+ char *buf) \
	1794	+{ \
	1795	+ struct iscsi_cls_conn *conn = iscsi_dev_to_conn(dev->parent); \
	1796	+ struct iscsi_transport *t = conn->transport; \
	1797	+ struct iscsi_endpoint *ep; \
	1798	+ ssize_t rc; \
	1799	+ \
	1800	+ /* \
	1801	+ * Need to make sure ep_disconnect does not free the LLD's \
	1802	+ * interconnect resources while we are trying to read them. \
	1803	+ */ \
	1804	+ mutex_lock(&conn->ep_mutex); \
	1805	+ ep = conn->ep; \
	1806	+ if (!ep && t->ep_connect) { \
	1807	+ mutex_unlock(&conn->ep_mutex); \
	1808	+ return -ENOTCONN; \
	1809	+ } \
	1810	+ \
	1811	+ if (ep) \
	1812	+ rc = t->get_ep_param(ep, param, buf); \
	1813	+ else \
	1814	+ rc = t->get_conn_param(conn, param, buf); \
	1815	+ mutex_unlock(&conn->ep_mutex); \
	1816	+ return rc; \
	1817	+}
	1818	+
	1819	+#define iscsi_conn_ep_attr(field, param) \
	1820	+ iscsi_conn_ep_attr_show(param) \
	1821	+static ISCSI_CLASS_ATTR(conn, field, S_IRUGO, \
	1822	+ show_conn_ep_param_##param, NULL);
	1823	+
	1824	+iscsi_conn_ep_attr(address, ISCSI_PARAM_CONN_ADDRESS);
	1825	+iscsi_conn_ep_attr(port, ISCSI_PARAM_CONN_PORT);
1791	1826
1792	1827	/*
1793	1828	* iSCSI session attrs
...	...	@@ -101,6 +101,8 @@
101	101	void (destroy_conn) (struct iscsi_cls_conn conn);
102	102	int (set_param) (struct iscsi_cls_conn conn, enum iscsi_param param,
103	103	char *buf, int buflen);
	104	+ int (get_ep_param) (struct iscsi_endpoint ep, enum iscsi_param param,
	105	+ char *buf);
104	106	int (get_conn_param) (struct iscsi_cls_conn conn,
105	107	enum iscsi_param param, char *buf);
106	108	int (get_session_param) (struct iscsi_cls_session session,