[PATCH net-next 1/2] net: avoid a dev refcount in ip_mc_find_dev()
From: Eric Dumazet <hidden>
Date: 2010-10-19 10:39:24
We hold RTNL in ip_mc_find_dev(), no need to touch device refcount. Signed-off-by: Eric Dumazet <redacted> --- net/ipv4/fib_frontend.c | 2 +- net/ipv4/igmp.c | 4 ++-- 2 files changed, 3 insertions(+), 3 deletions(-)
diff --git a/net/ipv4/fib_frontend.c b/net/ipv4/fib_frontend.c
index 3df057e..36e27c2 100644
--- a/net/ipv4/fib_frontend.c
+++ b/net/ipv4/fib_frontend.c@@ -153,7 +153,7 @@ static void fib_flush(struct net *net) * @addr: the source address * @devref: if true, take a reference on the found device * - * If a caller uses devref=false, it should be protected by RCU + * If a caller uses devref=false, it should be protected by RCU, or RTNL */ struct net_device *__ip_dev_find(struct net *net, __be32 addr, bool devref) {
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index 25f3396..a525328 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c@@ -1418,6 +1418,7 @@ void ip_mc_destroy_dev(struct in_device *in_dev) write_unlock_bh(&in_dev->mc_list_lock); } +/* RTNL is locked */ static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr) { struct flowi fl = { .nl_u = { .ip4_u =
@@ -1433,10 +1434,9 @@ static struct in_device *ip_mc_find_dev(struct net *net, struct ip_mreqn *imr) return idev; } if (imr->imr_address.s_addr) { - dev = ip_dev_find(net, imr->imr_address.s_addr); + dev = __ip_dev_find(net, imr->imr_address.s_addr, false); if (!dev) return NULL; - dev_put(dev); } if (!dev && !ip_route_output_key(net, &rt, &fl)) {