netlink: Adding inode field to /proc/net/netlink

The Inode field in /proc/net/{tcp,udp,packet,raw,...} is useful to know the types of
file descriptors associated to a process. Actually lsof utility uses the field.
Unfortunately, unlike /proc/net/{tcp,udp,packet,raw,...}, /proc/net/netlink doesn't have the field.
This patch adds the field to /proc/net/netlink.
Signed-off-by: Masatake YAMATO <yamato@redhat.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/netlink/af_netlink.c

@@ -1978,12 +1978,12 @@ static int netlink_seq_show(struct seq_file *seq, void *v)
 	if (v == SEQ_START_TOKEN)
 		seq_puts(seq,
 			 "sk       Eth Pid    Groups   "
-			 "Rmem     Wmem     Dump     Locks     Drops\n");
+			 "Rmem     Wmem     Dump     Locks     Drops     Inode\n");
 	else {
 		struct sock *s = v;
 		struct netlink_sock *nlk = nlk_sk(s);
 
-		seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d\n",
+		seq_printf(seq, "%p %-3d %-6d %08x %-8d %-8d %p %-8d %-8d %-8lu\n",
 			   s,
 			   s->sk_protocol,
 			   nlk->pid,
@@ -1992,7 +1992,8 @@ static int netlink_seq_show(struct seq_file *seq, void *v)
 			   sk_wmem_alloc_get(s),
 			   nlk->cb,
 			   atomic_read(&s->sk_refcnt),
-			   atomic_read(&s->sk_drops)
+			   atomic_read(&s->sk_drops),
+			   sock_i_ino(s)
 			);
 
 	}