netfilter: nf_conntrack: use mod_timer_pending() for conntrack refresh
Use mod_timer_pending() instead of atomic sequence of del_timer()/
add_timer(). mod_timer_pending() does not rearm an inactive timer,
so we don't need the conntrack lock anymore to make sure we don't
accidentally rearm a timer of a conntrack which is in the process
of being destroyed.
With this change, we don't need to take the global lock anymore at all,
counter updates can be performed under the per-conntrack lock.
Signed-off-by: Patrick McHardy <kaber@trash.net>
diff --git a/net/netfilter/nf_conntrack_core.c b/net/netfilter/nf_conntrack_core.c
index edf9569..d8dffe7 100644
--- a/net/netfilter/nf_conntrack_core.c
+++ b/net/netfilter/nf_conntrack_core.c
@@ -807,8 +807,6 @@
NF_CT_ASSERT(ct->timeout.data == (unsigned long)ct);
NF_CT_ASSERT(skb);
- spin_lock_bh(&nf_conntrack_lock);
-
/* Only update if this is not a fixed timeout */
if (test_bit(IPS_FIXED_TIMEOUT_BIT, &ct->status))
goto acct;
@@ -822,11 +820,8 @@
/* Only update the timeout if the new timeout is at least
HZ jiffies from the old timeout. Need del_timer for race
avoidance (may already be dying). */
- if (newtime - ct->timeout.expires >= HZ
- && del_timer(&ct->timeout)) {
- ct->timeout.expires = newtime;
- add_timer(&ct->timeout);
- }
+ if (newtime - ct->timeout.expires >= HZ)
+ mod_timer_pending(&ct->timeout, newtime);
}
acct:
@@ -835,13 +830,13 @@
acct = nf_conn_acct_find(ct);
if (acct) {
+ spin_lock_bh(&ct->lock);
acct[CTINFO2DIR(ctinfo)].packets++;
acct[CTINFO2DIR(ctinfo)].bytes +=
skb->len - skb_network_offset(skb);
+ spin_unlock_bh(&ct->lock);
}
}
-
- spin_unlock_bh(&nf_conntrack_lock);
}
EXPORT_SYMBOL_GPL(__nf_ct_refresh_acct);
@@ -853,14 +848,14 @@
if (do_acct) {
struct nf_conn_counter *acct;
- spin_lock_bh(&nf_conntrack_lock);
acct = nf_conn_acct_find(ct);
if (acct) {
+ spin_lock_bh(&ct->lock);
acct[CTINFO2DIR(ctinfo)].packets++;
acct[CTINFO2DIR(ctinfo)].bytes +=
skb->len - skb_network_offset(skb);
+ spin_unlock_bh(&ct->lock);
}
- spin_unlock_bh(&nf_conntrack_lock);
}
if (del_timer(&ct->timeout)) {