netlink: Export genl_lock() API for use by modules

This lets kernel modules which use genl netlink APIs serialize netlink
processing.

Signed-off-by: James Chapman <[e-mail]>
Reviewed-by: Randy Dunlap <[e-mail]>
Signed-off-by: David S. Miller <[e-mail]>

include/linux/genetlink.h

···
 
 #define CTRL_ATTR_MCAST_GRP_MAX (__CTRL_ATTR_MCAST_GRP_MAX - 1)
 
+#ifdef __KERNEL__
+
+/* All generic netlink requests are serialized by a global lock.  */
+extern void genl_lock(void);
+extern void genl_unlock(void);
+
+#endif /* __KERNEL__ */
+
 #endif	/* __LINUX_GENERIC_NETLINK_H */

net/netlink/genetlink.c

···
 
 static DEFINE_MUTEX(genl_mutex); /* serialization of message processing */
 
-static inline void genl_lock(void)
+void genl_lock(void)
 {
 	mutex_lock(&genl_mutex);
 }
+EXPORT_SYMBOL(genl_lock);
 
-static inline void genl_unlock(void)
+void genl_unlock(void)
 {
 	mutex_unlock(&genl_mutex);
 }
+EXPORT_SYMBOL(genl_unlock);
 
 #define GENL_FAM_TAB_SIZE	16
 #define GENL_FAM_TAB_MASK	(GENL_FAM_TAB_SIZE - 1)