inet: RCU changes in inetdev_by_index()
Convert inetdev_by_index() to not increment in_dev refcount.
Callers hold RCU or RTNL, and should not decrement in_dev refcount.
Signed-off-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/ipv4/devinet.c b/net/ipv4/devinet.c
index c2ff48f..dc94b03 100644
--- a/net/ipv4/devinet.c
+++ b/net/ipv4/devinet.c
@@ -403,6 +403,9 @@
return inet_insert_ifa(ifa);
}
+/* Caller must hold RCU or RTNL :
+ * We dont take a reference on found in_device
+ */
struct in_device *inetdev_by_index(struct net *net, int ifindex)
{
struct net_device *dev;
@@ -411,7 +414,7 @@
rcu_read_lock();
dev = dev_get_by_index_rcu(net, ifindex);
if (dev)
- in_dev = in_dev_get(dev);
+ in_dev = rcu_dereference_rtnl(dev->ip_ptr);
rcu_read_unlock();
return in_dev;
}
@@ -453,8 +456,6 @@
goto errout;
}
- __in_dev_put(in_dev);
-
for (ifap = &in_dev->ifa_list; (ifa = *ifap) != NULL;
ifap = &ifa->ifa_next) {
if (tb[IFA_LOCAL] &&
diff --git a/net/ipv4/fib_semantics.c b/net/ipv4/fib_semantics.c
index 0f80dfc..6734c9c 100644
--- a/net/ipv4/fib_semantics.c
+++ b/net/ipv4/fib_semantics.c
@@ -590,32 +590,29 @@
if (!dev)
goto out;
dev_hold(dev);
- err = -ENETDOWN;
- if (!(dev->flags & IFF_UP))
- goto out;
- err = 0;
-out:
- rcu_read_unlock();
- return err;
+ err = (dev->flags & IFF_UP) ? 0 : -ENETDOWN;
} else {
struct in_device *in_dev;
if (nh->nh_flags & (RTNH_F_PERVASIVE | RTNH_F_ONLINK))
return -EINVAL;
+ rcu_read_lock();
+ err = -ENODEV;
in_dev = inetdev_by_index(net, nh->nh_oif);
if (in_dev == NULL)
- return -ENODEV;
- if (!(in_dev->dev->flags & IFF_UP)) {
- in_dev_put(in_dev);
- return -ENETDOWN;
- }
+ goto out;
+ err = -ENETDOWN;
+ if (!(in_dev->dev->flags & IFF_UP))
+ goto out;
nh->nh_dev = in_dev->dev;
dev_hold(nh->nh_dev);
nh->nh_scope = RT_SCOPE_HOST;
- in_dev_put(in_dev);
+ err = 0;
}
- return 0;
+out:
+ rcu_read_unlock();
+ return err;
}
static inline unsigned int fib_laddr_hashfn(__be32 val)
diff --git a/net/ipv4/igmp.c b/net/ipv4/igmp.c
index a525328..c8877c6 100644
--- a/net/ipv4/igmp.c
+++ b/net/ipv4/igmp.c
@@ -1429,8 +1429,6 @@
if (imr->imr_ifindex) {
idev = inetdev_by_index(net, imr->imr_ifindex);
- if (idev)
- __in_dev_put(idev);
return idev;
}
if (imr->imr_address.s_addr) {
diff --git a/net/ipv4/ip_gre.c b/net/ipv4/ip_gre.c
index 9d421f4..d0ffcbe 100644
--- a/net/ipv4/ip_gre.c
+++ b/net/ipv4/ip_gre.c
@@ -1245,10 +1245,8 @@
if (ipv4_is_multicast(t->parms.iph.daddr) && t->mlink) {
struct in_device *in_dev;
in_dev = inetdev_by_index(dev_net(dev), t->mlink);
- if (in_dev) {
+ if (in_dev)
ip_mc_dec_group(in_dev, t->parms.iph.daddr);
- in_dev_put(in_dev);
- }
}
return 0;
}