bpf: Remove attach_type in bpf_netns_link

Use attach_type in bpf_link, and remove it in bpf_netns_link.
And move netns_type field to the end to fill the byte hole.

Signed-off-by: Tao Chen <[email protected]>
Signed-off-by: Andrii Nakryiko <[email protected]>
Reviewed-by: Jakub Sitnicki <[email protected]>
Acked-by: Jiri Olsa <[email protected]>
Acked-by: John Fastabend <[email protected]>
Link: https://lore.kernel.org/bpf/[email protected]

Author: Tao Chen

kernel/bpf/net_namespace.c

@@ -11,8 +11,6 @@
 
 struct bpf_netns_link {
 	struct bpf_link	link;
-	enum bpf_attach_type type;
-	enum netns_bpf_attach_type netns_type;
 
 	/* We don't hold a ref to net in order to auto-detach the link
 	 * when netns is going away. Instead we rely on pernet
@@ -21,6 +19,7 @@ struct bpf_netns_link {
 	 */
 	struct net *net;
 	struct list_head node; /* node in list of links attached to net */
+	enum netns_bpf_attach_type netns_type;
 };
 
 /* Protects updates to netns_bpf */
@@ -216,7 +215,7 @@ static int bpf_netns_link_fill_info(const struct bpf_link *link,
 	mutex_unlock(&netns_bpf_mutex);
 
 	info->netns.netns_ino = inum;
-	info->netns.attach_type = net_link->type;
+	info->netns.attach_type = link->attach_type;
 	return 0;
 }
 
@@ -230,7 +229,7 @@ static void bpf_netns_link_show_fdinfo(const struct bpf_link *link,
 		   "netns_ino:\t%u\n"
 		   "attach_type:\t%u\n",
 		   info.netns.netns_ino,
-		   info.netns.attach_type);
+		   link->attach_type);
 }
 
 static const struct bpf_link_ops bpf_netns_link_ops = {
@@ -503,7 +502,6 @@ int netns_bpf_link_create(const union bpf_attr *attr, struct bpf_prog *prog)
 	bpf_link_init(&net_link->link, BPF_LINK_TYPE_NETNS,
 		      &bpf_netns_link_ops, prog, type);
 	net_link->net = net;
-	net_link->type = type;
 	net_link->netns_type = netns_type;
 
 	err = bpf_link_prime(&net_link->link, &link_primer);