Commit 0cc09020 authored by Florian Westphal's avatar Florian Westphal Committed by David S. Miller

rtnetlink: small rtnl lock pushdown

instead of rtnl lock/unload at the top level, push it down
to the called function.

This is just an intermediate step, next commit switches protection
of the rtnl_link ops table to rcu, in which case (for dumps) the
rtnl lock is acquired only by the netlink dumper infrastructure
(current lock/unlock/dump/lock/unlock rtnl sequence becomes
 rcu lock/rcu unlock/dump).
Signed-off-by: default avatarFlorian Westphal <fw@strlen.de>
Reviewed-by: default avatarHannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 019a3169
...@@ -4178,9 +4178,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, ...@@ -4178,9 +4178,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
rtnl_dumpit_func dumpit; rtnl_dumpit_func dumpit;
u16 min_dump_alloc = 0; u16 min_dump_alloc = 0;
rtnl_lock();
dumpit = rtnl_get_dumpit(family, type); dumpit = rtnl_get_dumpit(family, type);
if (dumpit == NULL) if (dumpit == NULL)
return -EOPNOTSUPP; goto err_unlock;
refcount_inc(&rtnl_msg_handlers_ref[family]); refcount_inc(&rtnl_msg_handlers_ref[family]);
...@@ -4196,23 +4198,28 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, ...@@ -4196,23 +4198,28 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh,
}; };
err = netlink_dump_start(rtnl, skb, nlh, &c); err = netlink_dump_start(rtnl, skb, nlh, &c);
} }
rtnl_lock();
refcount_dec(&rtnl_msg_handlers_ref[family]); refcount_dec(&rtnl_msg_handlers_ref[family]);
return err; return err;
} }
rtnl_lock();
doit = rtnl_get_doit(family, type); doit = rtnl_get_doit(family, type);
if (doit == NULL) if (doit == NULL)
return -EOPNOTSUPP; goto err_unlock;
return doit(skb, nlh, extack); err = doit(skb, nlh, extack);
rtnl_unlock();
return err;
err_unlock:
rtnl_unlock();
return -EOPNOTSUPP;
} }
static void rtnetlink_rcv(struct sk_buff *skb) static void rtnetlink_rcv(struct sk_buff *skb)
{ {
rtnl_lock();
netlink_rcv_skb(skb, &rtnetlink_rcv_msg); netlink_rcv_skb(skb, &rtnetlink_rcv_msg);
rtnl_unlock();
} }
static int rtnetlink_bind(struct net *net, int group) static int rtnetlink_bind(struct net *net, int group)
......
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