[DCCP]: fix theoretical ccids_{read,write}_lock() race

Make sure that spin_unlock_wait() is properly ordered wrt atomic_inc().

(akpm: can't we convert this code to use rwlocks?)

Signed-off-by: Oleg Nesterov <oleg@tv-sign.ru>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Oleg Nesterov 2007-08-10 15:21:17 -07:00 committed by David S. Miller
parent b5890d8ba4
commit d725fdc802

View file

@ -40,6 +40,7 @@ static inline void ccids_write_unlock(void)
static inline void ccids_read_lock(void)
{
atomic_inc(&ccids_lockct);
smp_mb__after_atomic_inc();
spin_unlock_wait(&ccids_lock);
}