Subject: Revert "batman-adv: genetlink: move to smaller ops wherever possible"
From: Sven Eckelmann <[email-masked]>
Date: Sat, 24 Oct 2020 22:51:23 +0200

The netlink genl_ops interface was splitted into two parts for Linux 5.10.
The batman-adv code changed to the new one because it doesn't use the more
complex policy handling of genl_ops. But the backports-5.8-1 version in
OpenWrt doesn't yet support the new genl_small_ops.

This patch must be dropped directly when OpenWrt switches to backports-5.10
or newer - otherwise it will not work as expected.

This reverts commit 725b4ef5be840cfcd0ca33b9393c14dee40c10f7.

diff --git a/compat-include/net/genetlink.h b/compat-include/net/genetlink.h
index f16355febac42294491531a3f8049bc680560d0c..d1f80cd88503cdd11e9051f2e90ea533bee89a67 100644
--- a/compat-include/net/genetlink.h
+++ b/compat-include/net/genetlink.h
@@ -31,17 +31,15 @@ void batadv_genl_dump_check_consistent(struct netlink_callback *cb,
 #endif /* LINUX_VERSION_IS_LESS(4, 15, 0) */

-#if LINUX_VERSION_IS_LESS(5, 10, 0)
-
 #if LINUX_VERSION_IS_LESS(5, 2, 0)
+
 enum genl_validate_flags {
 	GENL_DONT_VALIDATE_STRICT		= BIT(0),
 	GENL_DONT_VALIDATE_DUMP			= BIT(1),
 	GENL_DONT_VALIDATE_DUMP_STRICT		= BIT(2),
 };
-#endif /* LINUX_VERSION_IS_LESS(5, 2, 0) */
 
-struct batadv_genl_small_ops {
+struct batadv_genl_ops {
 	int		       (*doit)(struct sk_buff *skb,
 				       struct genl_info *info);
 	int		       (*dumpit)(struct sk_buff *skb,
@@ -70,9 +68,9 @@ struct batadv_genl_family {
 			 struct genl_info *info);
         void (*post_doit)(const struct genl_ops *ops, struct sk_buff *skb,
 			  struct genl_info *info);
-	const struct batadv_genl_small_ops *small_ops;
+	const struct batadv_genl_ops *ops;
 	const struct genl_multicast_group *mcgrps;
-	unsigned int n_small_ops;
+	unsigned int n_ops;
 	unsigned int n_mcgrps;
 	struct module *module;
 
@@ -96,32 +94,24 @@ static inline int batadv_genl_register_family(struct batadv_genl_family *family)
 	family->family.pre_doit = family->pre_doit;
 	family->family.post_doit = family->post_doit;
 	family->family.mcgrps = family->mcgrps;
-	family->family.n_ops = family->n_small_ops;
+	family->family.n_ops = family->n_ops;
 	family->family.n_mcgrps = family->n_mcgrps;
 	family->family.module = family->module;
 
-	ops = kzalloc(sizeof(*ops) * family->n_small_ops, GFP_KERNEL);
+	ops = kzalloc(sizeof(*ops) * family->n_ops, GFP_KERNEL);
 	if (!ops)
 		return -ENOMEM;
 
 	for (i = 0; i < family->family.n_ops; i++) {
-		ops[i].doit = family->small_ops[i].doit;
-		ops[i].dumpit = family->small_ops[i].dumpit;
-		ops[i].done = family->small_ops[i].done;
-		ops[i].cmd = family->small_ops[i].cmd;
-		ops[i].internal_flags = family->small_ops[i].internal_flags;
-		ops[i].flags = family->small_ops[i].flags;
-#if LINUX_VERSION_IS_GEQ(5, 2, 0)
-		ops[i].validate = family->small_ops[i].validate;
-#else
+		ops[i].doit = family->ops[i].doit;
+		ops[i].dumpit = family->ops[i].dumpit;
+		ops[i].done = family->ops[i].done;
+		ops[i].cmd = family->ops[i].cmd;
+		ops[i].internal_flags = family->ops[i].internal_flags;
+		ops[i].flags = family->ops[i].flags;
 		ops[i].policy = family->policy;
-#endif
 	}
 
-#if LINUX_VERSION_IS_GEQ(5, 2, 0)
-	family->family.policy = family->policy;
-#endif
-
 	family->family.ops = ops;
 	family->copy_ops = ops;
 
@@ -136,7 +126,7 @@ typedef struct genl_ops batadv_genl_ops_old;
 #define batadv_post_doit(__x, __y, __z) \
 	batadv_post_doit(const batadv_genl_ops_old *ops, __y, __z)
 
-#define genl_small_ops batadv_genl_small_ops
+#define genl_ops batadv_genl_ops
 #define genl_family batadv_genl_family
 
 #define genl_register_family(family) \
@@ -160,6 +150,6 @@ batadv_genl_unregister_family(struct batadv_genl_family *family)
 	genlmsg_multicast_netns(&(_family)->family, _net, _skb, _portid, \
 				_group, _flags)
 
-#endif /* LINUX_VERSION_IS_LESS(5, 10, 0) */
+#endif /* LINUX_VERSION_IS_LESS(5, 2, 0) */
 
 #endif /* _NET_BATMAN_ADV_COMPAT_NET_GENETLINK_H_ */
diff --git a/net/batman-adv/netlink.c b/net/batman-adv/netlink.c
index 97bcf149633d850ff4fcece6d7dc0d799adb1444..a8f15c04826af1144db655887b754758fc5ab47a 100644
--- a/net/batman-adv/netlink.c
+++ b/net/batman-adv/netlink.c
@@ -1351,7 +1351,7 @@ static void batadv_post_doit(const struct genl_ops *ops, struct sk_buff *skb,
 	}
 }
 
-static const struct genl_small_ops batadv_netlink_ops[] = {
+static const struct genl_ops batadv_netlink_ops[] = {
 	{
 		.cmd = BATADV_CMD_GET_MESH,
 		.validate = GENL_DONT_VALIDATE_STRICT | GENL_DONT_VALIDATE_DUMP,
@@ -1485,8 +1485,8 @@ struct genl_family batadv_netlink_family __ro_after_init = {
 	.pre_doit = batadv_pre_doit,
 	.post_doit = batadv_post_doit,
 	.module = THIS_MODULE,
-	.small_ops = batadv_netlink_ops,
-	.n_small_ops = ARRAY_SIZE(batadv_netlink_ops),
+	.ops = batadv_netlink_ops,
+	.n_ops = ARRAY_SIZE(batadv_netlink_ops),
 	.mcgrps = batadv_netlink_mcgrps,
 	.n_mcgrps = ARRAY_SIZE(batadv_netlink_mcgrps),
 };