dcb: use __dev_get_by_name instead of dev_get_by_name to find interface (d9ac62be) · Commits · 戴 / test

The following call chain indicates that dcb_doit() is protected under rtnl_lock. So if we use __dev_get_by_name() instead of dev_get_by_name() to find interface handlers in it, this would help us avoid to change interface reference counter. rtnetlink_rcv() rtnl_lock() netlink_rcv_skb() dcb_doit() rtnl_unlock() Cc: John Fastabend <john.r.fastabend@intel.com> Signed-off-by:

Ying Xue <ying.xue@windriver.com> Signed-off-by:

David S. Miller <davem@davemloft.net>

net/dcb/dcbnl.c

+5 −10

Original line number	Diff line number	Diff line
		@@ -1688,21 +1688,17 @@ static int dcb_doit(struct sk_buff skb, struct nlmsghdr nlh)
		if (!tb[DCB_ATTR_IFNAME])
		return -EINVAL;

		netdev = dev_get_by_name(net, nla_data(tb[DCB_ATTR_IFNAME]));
		netdev = __dev_get_by_name(net, nla_data(tb[DCB_ATTR_IFNAME]));
		if (!netdev)
		return -ENODEV;

		if (!netdev->dcbnl_ops) {
		ret = -EOPNOTSUPP;
		goto out;
		}
		if (!netdev->dcbnl_ops)
		return -EOPNOTSUPP;

		reply_skb = dcbnl_newmsg(fn->type, dcb->cmd, portid, nlh->nlmsg_seq,
		nlh->nlmsg_flags, &reply_nlh);
		if (!reply_skb) {
		ret = -ENOBUFS;
		goto out;
		}
		if (!reply_skb)
		return -ENOBUFS;

		ret = fn->cb(netdev, nlh, nlh->nlmsg_seq, tb, reply_skb);
		if (ret < 0) {
		@@ -1714,7 +1710,6 @@ static int dcb_doit(struct sk_buff skb, struct nlmsghdr nlh)

		ret = rtnl_unicast(reply_skb, net, portid);
		out:
		dev_put(netdev);
		return ret;
		}

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