[PATCH v2 net-next 4/7] rtnetlink: small rtnl lock pushdown
flat view
STALE3354d
REVIEWED: 1 (0M)
From: Florian Westphal <fw@strlen.de>
Date: 2017-08-09 18:41:53
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
1 review trailer.
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 <redacted> --- No changes since v1. net/core/rtnetlink.c | 19 +++++++++++++------ 1 file 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)
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2.13.0