[PATCH] net: make get_net_ns_by_fd inline if NET_NS is disabled

[Changbin Du <changbin.du@gmail.com>]

The function get_net_ns_by_fd() could be inlined when NET_NS is not
enabled.

Signed-off-by: Changbin Du <changbin.du@gmail.com>
---
 include/net/net_namespace.h | 8 +++++++-
 net/core/net_namespace.c    | 8 +-------
 2 files changed, 8 insertions(+), 8 deletions(-)

diff --git a/include/net/net_namespace.h b/include/net/net_namespace.h
index fa5887143f0d..0a25f95691d9 100644
--- a/include/net/net_namespace.h
+++ b/include/net/net_namespace.h
@@ -184,6 +184,8 @@ struct net *copy_net_ns(unsigned long flags, struct user_namespace *user_ns,
 void net_ns_get_ownership(const struct net *net, kuid_t *uid, kgid_t *gid);
 
 void net_ns_barrier(void);
+
+struct net *get_net_ns_by_fd(int fd);
 #else /* CONFIG_NET_NS */
 #include <linux/sched.h>
 #include <linux/nsproxy.h>
@@ -203,13 +205,17 @@ static inline void net_ns_get_ownership(const struct net *net,
 }
 
 static inline void net_ns_barrier(void) {}
+
+static inline struct net *get_net_ns_by_fd(int fd)
+{
+	return ERR_PTR(-EINVAL);
+}
 #endif /* CONFIG_NET_NS */
 
 
 extern struct list_head net_namespace_list;
 
 struct net *get_net_ns_by_pid(pid_t pid);
-struct net *get_net_ns_by_fd(int fd);
 
 #ifdef CONFIG_SYSCTL
 void ipx_register_sysctl(void);
diff --git a/net/core/net_namespace.c b/net/core/net_namespace.c
index 43b6ac4c4439..6a0d9583d69c 100644
--- a/net/core/net_namespace.c
+++ b/net/core/net_namespace.c
@@ -660,14 +660,8 @@ struct net *get_net_ns_by_fd(int fd)
 	fput(file);
 	return net;
 }
-
-#else
-struct net *get_net_ns_by_fd(int fd)
-{
-	return ERR_PTR(-EINVAL);
-}
-#endif
 EXPORT_SYMBOL_GPL(get_net_ns_by_fd);
+#endif
 
 struct net *get_net_ns_by_pid(pid_t pid)
 {
-- 
2.30.2