ipv6: addrlabel: rework ip6addrlbl_get()

If we allocate skb before the lookup, we can use RCU
without the need of ip6addrlbl_hold()

This means that the following patch can get rid of refcounting.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Eric Dumazet 2017-10-09 09:52:24 -07:00 committed by David S. Miller
parent 1ee87d7a31
commit 66c77ff3a0

View File

@ -546,38 +546,28 @@ static int ip6addrlbl_get(struct sk_buff *in_skb, struct nlmsghdr *nlh,
return -EINVAL;
addr = nla_data(tb[IFAL_ADDRESS]);
skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
if (!skb)
return -ENOBUFS;
err = -ESRCH;
rcu_read_lock();
p = __ipv6_addr_label(net, addr, ipv6_addr_type(addr), ifal->ifal_index);
if (p && !ip6addrlbl_hold(p))
p = NULL;
lseq = net->ipv6.ip6addrlbl_table.seq;
if (p)
err = ip6addrlbl_fill(skb, p, lseq,
NETLINK_CB(in_skb).portid,
nlh->nlmsg_seq,
RTM_NEWADDRLABEL, 0);
rcu_read_unlock();
if (!p) {
err = -ESRCH;
goto out;
}
skb = nlmsg_new(ip6addrlbl_msgsize(), GFP_KERNEL);
if (!skb) {
ip6addrlbl_put(p);
return -ENOBUFS;
}
err = ip6addrlbl_fill(skb, p, lseq,
NETLINK_CB(in_skb).portid, nlh->nlmsg_seq,
RTM_NEWADDRLABEL, 0);
ip6addrlbl_put(p);
if (err < 0) {
WARN_ON(err == -EMSGSIZE);
kfree_skb(skb);
goto out;
} else {
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
}
err = rtnl_unicast(skb, net, NETLINK_CB(in_skb).portid);
out:
return err;
}