From e5ed639913eea3e4783a550291775ab78dd84966 Mon Sep 17 00:00:00 2001 From: Herbert Xu Date: Mon, 3 Oct 2005 14:35:55 -0700 Subject: [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 Signed-off-by: David S. Miller --- include/linux/inetdevice.h | 12 ++++++++++-- 1 file changed, 10 insertions(+), 2 deletions(-) (limited to 'include/linux/inetdevice.h') 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; } -- cgit v1.2.3-59-g8ed1b