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authorHerbert Xu <herbert@gondor.apana.org.au>2005-10-04 01:35:55 +0400
committerDavid S. Miller <davem@davemloft.net>2005-10-04 01:35:55 +0400
commite5ed639913eea3e4783a550291775ab78dd84966 (patch)
treee6e915aa686d2a7125181fc83a847e1955a8ba46 /include/linux
parenta5e7c210fefd2454c757a3542e41063407ca7108 (diff)
downloadlinux-e5ed639913eea3e4783a550291775ab78dd84966.tar.xz
[IPV4]: Replace __in_dev_get with __in_dev_get_rcu/rtnl
The following patch renames __in_dev_get() to __in_dev_get_rtnl() and introduces __in_dev_get_rcu() to cover the second case. 1) RCU with refcnt should use in_dev_get(). 2) RCU without refcnt should use __in_dev_get_rcu(). 3) All others must hold RTNL and use __in_dev_get_rtnl(). There is one exception in net/ipv4/route.c which is in fact a pre-existing race condition. I've marked it as such so that we remember to fix it. This patch is based on suggestions and prior work by Suzanne Wood and Paul McKenney. Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/linux')
-rw-r--r--include/linux/inetdevice.h12
1 files changed, 10 insertions, 2 deletions
diff --git a/include/linux/inetdevice.h b/include/linux/inetdevice.h
index 7e1e15f934f3..fd7af86151b1 100644
--- a/include/linux/inetdevice.h
+++ b/include/linux/inetdevice.h
@@ -142,13 +142,21 @@ static __inline__ int bad_mask(u32 mask, u32 addr)
#define endfor_ifa(in_dev) }
+static inline struct in_device *__in_dev_get_rcu(const struct net_device *dev)
+{
+ struct in_device *in_dev = dev->ip_ptr;
+ if (in_dev)
+ in_dev = rcu_dereference(in_dev);
+ return in_dev;
+}
+
static __inline__ struct in_device *
in_dev_get(const struct net_device *dev)
{
struct in_device *in_dev;
rcu_read_lock();
- in_dev = dev->ip_ptr;
+ in_dev = __in_dev_get_rcu(dev);
if (in_dev)
atomic_inc(&in_dev->refcnt);
rcu_read_unlock();
@@ -156,7 +164,7 @@ in_dev_get(const struct net_device *dev)
}
static __inline__ struct in_device *
-__in_dev_get(const struct net_device *dev)
+__in_dev_get_rtnl(const struct net_device *dev)
{
return (struct in_device*)dev->ip_ptr;
}