inet: Remove rtnl_is_held arg of lwtunnel_valid_encap_type(_attr)?().

Commit f130a0cc1b4f ("inet: fix lwtunnel_valid_encap_type() lock
imbalance") added the rtnl_is_held argument as a temporary fix while
I'm converting nexthop and IPv6 routing table to per-netns RTNL or RCU.

Now all callers of lwtunnel_valid_encap_type() do not hold RTNL.

Let's remove the argument.

Signed-off-by: Kuniyuki Iwashima <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Jakub Kicinski <[e-mail]>

include/net/lwtunnel.h

···
 int lwtunnel_encap_del_ops(const struct lwtunnel_encap_ops *op,
 			   unsigned int num);
 int lwtunnel_valid_encap_type(u16 encap_type,
-			      struct netlink_ext_ack *extack,
-			      bool rtnl_is_held);
+			      struct netlink_ext_ack *extack);
 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
-				   struct netlink_ext_ack *extack,
-				   bool rtnl_is_held);
+				   struct netlink_ext_ack *extack);
 int lwtunnel_build_state(struct net *net, u16 encap_type,
 			 struct nlattr *encap,
 			 unsigned int family, const void *cfg,
···
 }
 
 static inline int lwtunnel_valid_encap_type(u16 encap_type,
-					    struct netlink_ext_ack *extack,
-					    bool rtnl_is_held)
+					    struct netlink_ext_ack *extack)
 {
 	NL_SET_ERR_MSG(extack, "CONFIG_LWTUNNEL is not enabled in this kernel");
 	return -EOPNOTSUPP;
 }
+
 static inline int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int len,
-						 struct netlink_ext_ack *extack,
-						 bool rtnl_is_held)
+						 struct netlink_ext_ack *extack)
 {
 	/* return 0 since we are not walking attr looking for
 	 * RTA_ENCAP_TYPE attribute on nexthops.

net/core/lwtunnel.c

···
 }
 EXPORT_SYMBOL_GPL(lwtunnel_build_state);
 
-int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack,
-			      bool rtnl_is_held)
+int lwtunnel_valid_encap_type(u16 encap_type, struct netlink_ext_ack *extack)
 {
 	const struct lwtunnel_encap_ops *ops;
 	int ret = -EINVAL;
···
 		const char *encap_type_str = lwtunnel_encap_str(encap_type);
 
 		if (encap_type_str) {
-			if (rtnl_is_held)
-				__rtnl_unlock();
 			request_module("rtnl-lwt-%s", encap_type_str);
-			if (rtnl_is_held)
-				rtnl_lock();
-
 			ops = rcu_access_pointer(lwtun_encaps[encap_type]);
 		}
 	}
···
 EXPORT_SYMBOL_GPL(lwtunnel_valid_encap_type);
 
 int lwtunnel_valid_encap_type_attr(struct nlattr *attr, int remaining,
-				   struct netlink_ext_ack *extack,
-				   bool rtnl_is_held)
+				   struct netlink_ext_ack *extack)
 {
 	struct rtnexthop *rtnh = (struct rtnexthop *)attr;
 	struct nlattr *nla_entype;
···
 				}
 				encap_type = nla_get_u16(nla_entype);
 
-				if (lwtunnel_valid_encap_type(encap_type,
-							      extack,
-							      rtnl_is_held) != 0)
+				if (lwtunnel_valid_encap_type(encap_type, extack))
 					return -EOPNOTSUPP;
 			}
 		}

net/ipv4/fib_frontend.c

···
 		case RTA_MULTIPATH:
 			err = lwtunnel_valid_encap_type_attr(nla_data(attr),
 							     nla_len(attr),
-							     extack, false);
+							     extack);
 			if (err < 0)
 				goto errout;
 			cfg->fc_mp = nla_data(attr);
···
 		case RTA_ENCAP_TYPE:
 			cfg->fc_encap_type = nla_get_u16(attr);
 			err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
-							extack, false);
+							extack);
 			if (err < 0)
 				goto errout;
 			break;

net/ipv4/nexthop.c

···
 		}
 
 		cfg->nh_encap_type = nla_get_u16(tb[NHA_ENCAP_TYPE]);
-		err = lwtunnel_valid_encap_type(cfg->nh_encap_type,
-						extack, false);
+		err = lwtunnel_valid_encap_type(cfg->nh_encap_type, extack);
 		if (err < 0)
 			goto out;
 

net/ipv6/route.c

···
 		rtnh = rtnh_next(rtnh, &remaining);
 	} while (rtnh_ok(rtnh, remaining));
 
-	return lwtunnel_valid_encap_type_attr(cfg->fc_mp, cfg->fc_mp_len,
-					      extack, false);
+	return lwtunnel_valid_encap_type_attr(cfg->fc_mp, cfg->fc_mp_len, extack);
 }
 
 static int rtm_to_fib6_config(struct sk_buff *skb, struct nlmsghdr *nlh,
···
 	if (tb[RTA_ENCAP_TYPE]) {
 		cfg->fc_encap_type = nla_get_u16(tb[RTA_ENCAP_TYPE]);
 
-		err = lwtunnel_valid_encap_type(cfg->fc_encap_type,
-						extack, false);
+		err = lwtunnel_valid_encap_type(cfg->fc_encap_type, extack);
 		if (err < 0)
 			goto errout;
 	}