Re: [PATCH net-next-2.6] rtnetlink: rtnl_setlink() and rtnl_getlink() changes

> Stephen, do you think we could change "ip link show dev ethX" to > let it use rtnl_getlink() instead of rtnl_dump_ifinfo() ? > > Thanks ! > > [PATCH net-next-2.6]rtnetlink: rtnl_setlink() and rtnl_getlink() changes > > rtnl_getlink() & rtnl_setlink() run with RTNL held, we can use > __dev_get_by_index() and __dev_get_by_name() variants and avoid > dev_hold()/dev_put() > > Adds to rtnl_getlink() the capability to find a device by its name, > not only by its index. > > Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com> > --- > net/core/rtnetlink.c | 38 +++++++++++++++++++------------------- > 1 files changed, 19 insertions(+), 19 deletions(-) > > diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c > index eb42873..ba13b09 100644 > --- a/net/core/rtnetlink.c > +++ b/net/core/rtnetlink.c > @@ -910,9 +910,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) > err = -EINVAL; > ifm = nlmsg_data(nlh); > if (ifm->ifi_index > 0) > - dev = dev_get_by_index(net, ifm->ifi_index); > + dev = __dev_get_by_index(net, ifm->ifi_index); > else if (tb[IFLA_IFNAME]) > - dev = dev_get_by_name(net, ifname); > + dev = __dev_get_by_name(net, ifname); > else > goto errout; > > @@ -922,11 +922,9 @@ static int rtnl_setlink(struct sk_buff *skb, struct nlmsghdr *nlh, void *arg) > } > > if ((err = validate_linkmsg(dev, tb)) < 0) > - goto errout_dev; > + goto errout; > > err = do_setlink(dev, ifm, tb, ifname, 0); > -errout_dev: > - dev_put(dev); > errout: > return err; > } > @@ -1154,6 +1152,7 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) > { > struct net *net = sock_net(skb->sk); > struct ifinfomsg *ifm; > + char ifname[IFNAMSIZ]; > struct nlattr *tb[IFLA_MAX+1]; > struct net_device *dev = NULL; > struct sk_buff *nskb; > @@ -1163,19 +1162,23 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) > if (err < 0) > return err; > > + if (tb[IFLA_IFNAME]) > + nla_strlcpy(ifname, tb[IFLA_IFNAME], IFNAMSIZ); > + > ifm = nlmsg_data(nlh); > - if (ifm->ifi_index > 0) { > - dev = dev_get_by_index(net, ifm->ifi_index); > - if (dev == NULL) > - return -ENODEV; > - } else > + if (ifm->ifi_index > 0) > + dev = __dev_get_by_index(net, ifm->ifi_index); > + else if (tb[IFLA_IFNAME]) > + dev = __dev_get_by_name(net, ifname); > + else > return -EINVAL; > > + if (dev == NULL) > + return -ENODEV; > + > nskb = nlmsg_new(if_nlmsg_size(dev), GFP_KERNEL); > - if (nskb == NULL) { > - err = -ENOBUFS; > - goto errout; > - } > + if (nskb == NULL) > + return -ENOBUFS; > > err = rtnl_fill_ifinfo(nskb, dev, RTM_NEWLINK, NETLINK_CB(skb).pid, > nlh->nlmsg_seq, 0, 0); > @@ -1183,11 +1186,8 @@ static int rtnl_getlink(struct sk_buff *skb, struct nlmsghdr* nlh, void *arg) > /* -EMSGSIZE implies BUG in if_nlmsg_size */ > WARN_ON(err == -EMSGSIZE); > kfree_skb(nskb); > - goto errout; > - } > - err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid); > -errout: > - dev_put(dev); > + } else > + err = rtnl_unicast(nskb, net, NETLINK_CB(skb).pid); > > return err; > }