diff options
| author | Florian Westphal <fw@strlen.de> | 2017-08-09 20:41:50 +0200 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2017-08-09 16:57:38 -0700 |
| commit | 0cc09020aefe832db23d63cd3a6c889ab7645eec (patch) | |
| tree | 5458da1272db981d04048d558e64baa5bdcdabbf /net/core/rtnetlink.c | |
| parent | 019a316992ee0d9832b1c480c899d6bdf2a0a77e (diff) | |
| download | lwn-0cc09020aefe832db23d63cd3a6c889ab7645eec.tar.gz lwn-0cc09020aefe832db23d63cd3a6c889ab7645eec.zip | |
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: Florian Westphal <fw@strlen.de>
Reviewed-by: Hannes Frederic Sowa <hannes@stressinduktion.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'net/core/rtnetlink.c')
| -rw-r--r-- | net/core/rtnetlink.c | 19 |
1 files changed, 13 insertions, 6 deletions
diff --git a/net/core/rtnetlink.c b/net/core/rtnetlink.c index c45a7c5e3232..be01d8e48661 100644 --- a/net/core/rtnetlink.c +++ b/net/core/rtnetlink.c @@ -4178,9 +4178,11 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, rtnl_dumpit_func dumpit; u16 min_dump_alloc = 0; + rtnl_lock(); + dumpit = rtnl_get_dumpit(family, type); if (dumpit == NULL) - return -EOPNOTSUPP; + goto err_unlock; refcount_inc(&rtnl_msg_handlers_ref[family]); @@ -4196,23 +4198,28 @@ static int rtnetlink_rcv_msg(struct sk_buff *skb, struct nlmsghdr *nlh, }; err = netlink_dump_start(rtnl, skb, nlh, &c); } - rtnl_lock(); refcount_dec(&rtnl_msg_handlers_ref[family]); return err; } + rtnl_lock(); doit = rtnl_get_doit(family, type); 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) { - rtnl_lock(); netlink_rcv_skb(skb, &rtnetlink_rcv_msg); - rtnl_unlock(); } static int rtnetlink_bind(struct net *net, int group) |