[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>

1 files changed, 15 insertions, 11 deletions

diff --git a/net/netfilter/nf_log.c b/net/netfilter/nf_log.c
index 814bab700db6..243d66b1c02c 100644
--- 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();
 }