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/dst.h | |
parent | 5a0d513b622ee41e117fc37e26e27e8ef42e8dae (diff) |
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/dst.h')
-rw-r--r-- | include/net/dst.h | 7 |
1 files changed, 6 insertions, 1 deletions
diff --git a/include/net/dst.h b/include/net/dst.h index 31a9fd39edb6..baf597890064 100644 --- a/include/net/dst.h +++ b/include/net/dst.h @@ -61,7 +61,6 @@ struct dst_entry { #define DST_NOPEER 0x0040 #define DST_FAKE_RTABLE 0x0080 #define DST_XFRM_TUNNEL 0x0100 -#define DST_RCU_FREE 0x0200 unsigned short pending_confirm; @@ -383,6 +382,12 @@ static inline void dst_free(struct dst_entry *dst) __dst_free(dst); } +static inline void dst_rcu_free(struct rcu_head *head) +{ + struct dst_entry *dst = container_of(head, struct dst_entry, rcu_head); + dst_free(dst); +} + static inline void dst_confirm(struct dst_entry *dst) { dst->pending_confirm = 1; |