Introduce mod_timer_noact() which for example is to replace the calls to
del_timer()/add_timer() in __nf_ct_refresh_acct(). It works like mod_timer()
but doesn't activate or modify the timeout of an inactive timer which is the
behaviour we want in order to be able to use timers as a means of
synchronization in nf_conntrack.

A later patch will modify __nf_ct_refresh_acct() to use mod_timer_noact()
which will then save one spin_lock_irqsave() / spin_lock_irqrestore() pair per
conntrack timer update. This will also get rid of the race we currently have
without adding more locking in nf_conntrack.

Signed-off-by: Martin Josefsson <redacted>

---
 include/linux/timer.h |    8 ++++++--
 kernel/relay.c        |    2 +-
 kernel/timer.c        |   40 +++++++++++++++++++++++++++++++++++-----
 3 files changed, 42 insertions(+), 8 deletions(-)

--- a/include/linux/timer.h	2009-02-17 10:55:33.427785986 -0800
+++ b/include/linux/timer.h	2009-02-17 11:04:10.291844534 -0800

@@ -25,6 +25,9 @@ struct timer_list {
 
 extern struct tvec_base boot_tvec_bases;
 
+#define TIMER_ACT	1
+#define TIMER_NOACT	0