[NETFILTER]: nfnetlink: use mutex instead of semaphore

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

1 files changed, 24 insertions, 11 deletions

diff --git a/net/netfilter/nfnetlink.c b/net/netfilter/nfnetlink.c
index bf23e489e4cd..7865a47c981e 100644
--- a/net/netfilter/nfnetlink.c
+++ b/net/netfilter/nfnetlink.c
@@ -28,6 +28,7 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 #include <net/sock.h>
+#include <net/netlink.h>
 #include <linux/init.h>
 #include <linux/spinlock.h>
 
@@ -51,16 +52,28 @@ static char __initdata nfversion[] = "0.30";
 
 static struct sock *nfnl = NULL;
 static struct nfnetlink_subsystem *subsys_table[NFNL_SUBSYS_COUNT];
-DECLARE_MUTEX(nfnl_sem);
+static DEFINE_MUTEX(nfnl_mutex);
 
-void nfnl_lock(void)
+static void nfnl_lock(void)
 {
-        nfnl_shlock();
+        mutex_lock(&nfnl_mutex);
 }
 
-void nfnl_unlock(void)
+static int nfnl_trylock(void)
 {
-        nfnl_shunlock();
+        return !mutex_trylock(&nfnl_mutex);
+}
+
+static void __nfnl_unlock(void)
+{
+        mutex_unlock(&nfnl_mutex);
+}
+
+static void nfnl_unlock(void)
+{
+        mutex_unlock(&nfnl_mutex);
+        if (nfnl->sk_receive_queue.qlen)
+                nfnl->sk_data_ready(nfnl, 0);
 }
 
 int nfnetlink_subsys_register(struct nfnetlink_subsystem *n)
@@ -248,11 +261,11 @@ static int nfnetlink_rcv_msg(struct sk_buff *skb,
         ss = nfnetlink_get_subsys(type);
         if (!ss) {
 #ifdef CONFIG_KMOD
-                /* don't call nfnl_shunlock, since it would reenter
+                /* don't call nfnl_unlock, since it would reenter
                  * with further packet processing */
-                up(&nfnl_sem);
+                __nfnl_unlock();
                 request_module("nfnetlink-subsys-%d", NFNL_SUBSYS_ID(type));
-                nfnl_shlock();
+                nfnl_lock();
                 ss = nfnetlink_get_subsys(type);
                 if (!ss)
 #endif
@@ -322,7 +335,7 @@ static void nfnetlink_rcv(struct sock *sk, int len)
         do {
                 struct sk_buff *skb;
 
-                if (nfnl_shlock_nowait())
+                if (nfnl_trylock())
                         return;
 
                 while ((skb = skb_dequeue(&sk->sk_receive_queue)) != NULL) {
@@ -337,9 +350,9 @@ static void nfnetlink_rcv(struct sock *sk, int len)
                         kfree_skb(skb);
                 }
 
-                /* don't call nfnl_shunlock, since it would reenter
+                /* don't call nfnl_unlock, since it would reenter
                  * with further packet processing */
-                up(&nfnl_sem);
+                __nfnl_unlock();
         } while(nfnl && nfnl->sk_receive_queue.qlen);
 }