diff options
| author | Eric Dumazet <eric.dumazet@gmail.com> | 2012-07-31 01:08:23 +0000 |
|---|---|---|
| committer | David S. Miller <davem@davemloft.net> | 2012-07-31 14:41:38 -0700 |
| commit | 54764bb647b2e847c512acf8d443df965da35000 (patch) | |
| tree | 3918f6f42679d0ebdcef230f28285f99d178be62 /include/net/inet_sock.h | |
| parent | 5a0d513b622ee41e117fc37e26e27e8ef42e8dae (diff) | |
| download | kernel-common-54764bb647b2e847c512acf8d443df965da35000.tar.gz kernel-common-54764bb647b2e847c512acf8d443df965da35000.tar.bz2 kernel-common-54764bb647b2e847c512acf8d443df965da35000.zip | |
ipv4: Restore old dst_free() behavior.
commit 404e0a8b6a55 (net: ipv4: fix RCU races on dst refcounts) tried
to solve a race but added a problem at device/fib dismantle time :
We really want to call dst_free() as soon as possible, even if sockets
still have dst in their cache.
dst_release() calls in free_fib_info_rcu() are not welcomed.
Root of the problem was that now we also cache output routes (in
nh_rth_output), we must use call_rcu() instead of call_rcu_bh() in
rt_free(), because output route lookups are done in process context.
Based on feedback and initial patch from David Miller (adding another
call_rcu_bh() call in fib, but it appears it was not the right fix)
I left the inet_sk_rx_dst_set() helper and added __rcu attributes
to nh_rth_output and nh_rth_input to better document what is going on in
this code.
Signed-off-by: Eric Dumazet <edumazet@google.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'include/net/inet_sock.h')
| -rw-r--r-- | include/net/inet_sock.h | 10 |
1 files changed, 3 insertions, 7 deletions
diff --git a/include/net/inet_sock.h b/include/net/inet_sock.h index e3fd34c83ac9..83b567fe1941 100644 --- a/include/net/inet_sock.h +++ b/include/net/inet_sock.h @@ -253,13 +253,9 @@ static inline void inet_sk_rx_dst_set(struct sock *sk, const struct sk_buff *skb { struct dst_entry *dst = skb_dst(skb); - if (atomic_inc_not_zero(&dst->__refcnt)) { - if (!(dst->flags & DST_RCU_FREE)) - dst->flags |= DST_RCU_FREE; - - sk->sk_rx_dst = dst; - inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; - } + dst_hold(dst); + sk->sk_rx_dst = dst; + inet_sk(sk)->rx_dst_ifindex = skb->skb_iif; } #endif /* _INET_SOCK_H */ |