[NETFILTER]: nf_log: switch logger registration/unregistration to mutex

The spinlock is only used in process context (register/unregister),
switch to a mutex.

Signed-off-by: Patrick McHardy <kaber@trash.net>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 814bab700db6d7802a07df0f9536fef8b28dce9a..243d66b1c02c53f48a511308a45c5a17c738f6b1 100644 (file)
--- a/net/netfilter/nf_log.c
+++ b/net/netfilter/nf_log.c
@@ -15,27 +15,31 @@
 #define NF_LOG_PREFIXLEN               128
 
 static struct nf_logger *nf_logging[NPROTO]; /* = NULL */
-static DEFINE_SPINLOCK(nf_log_lock);
+static DEFINE_MUTEX(nf_log_mutex);
 
 /* return EBUSY if somebody else is registered, EEXIST if the same logger
  * is registred, 0 on success. */
 int nf_log_register(int pf, struct nf_logger *logger)
 {
-       int ret = -EBUSY;
+       int ret;
 
        if (pf >= NPROTO)
                return -EINVAL;
 
        /* Any setup of logging members must be done before
         * substituting pointer. */
-       spin_lock(&nf_log_lock);
-       if (!nf_logging[pf]) {
+       ret = mutex_lock_interruptible(&nf_log_mutex);
+       if (ret < 0)
+               return ret;
+
+       if (!nf_logging[pf])
                rcu_assign_pointer(nf_logging[pf], logger);
-               ret = 0;
-       } else if (nf_logging[pf] == logger)
+       else if (nf_logging[pf] == logger)
                ret = -EEXIST;
+       else
+               ret = -EBUSY;
 
-       spin_unlock(&nf_log_lock);
+       mutex_unlock(&nf_log_mutex);
        return ret;
 }              
 EXPORT_SYMBOL(nf_log_register);
@@ -44,9 +48,9 @@ void nf_log_unregister_pf(int pf)
 {
        if (pf >= NPROTO)
                return;
-       spin_lock(&nf_log_lock);
+       mutex_lock(&nf_log_mutex);
        rcu_assign_pointer(nf_logging[pf], NULL);
-       spin_unlock(&nf_log_lock);
+       mutex_unlock(&nf_log_mutex);
 
        /* Give time to concurrent readers. */
        synchronize_rcu();
@@ -57,12 +61,12 @@ void nf_log_unregister_logger(struct nf_logger *logger)
 {
        int i;
 
-       spin_lock(&nf_log_lock);
+       mutex_lock(&nf_log_mutex);
        for (i = 0; i < NPROTO; i++) {
                if (nf_logging[i] == logger)
                        rcu_assign_pointer(nf_logging[i], NULL);
        }
-       spin_unlock(&nf_log_lock);
+       mutex_unlock(&nf_log_mutex);
 
        synchronize_rcu();
 }