ACPICA: Update version to 20100528

[firefly-linux-kernel-4.4.55.git] / net / core / sock.c

diff --git a/net/core/sock.c b/net/core/sock.c
index 37fe9b6adaded0fc2c278886f1cd0a5bdf86742c..2cf7f9f7e775105ceef0bd630fd981dab2262952 100644 (file)
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2007,6 +2007,39 @@ void release_sock(struct sock *sk)
 }
 EXPORT_SYMBOL(release_sock);
 
+/**
+ * lock_sock_fast - fast version of lock_sock
+ * @sk: socket
+ *
+ * This version should be used for very small section, where process wont block
+ * return false if fast path is taken
+ *   sk_lock.slock locked, owned = 0, BH disabled
+ * return true if slow path is taken
+ *   sk_lock.slock unlocked, owned = 1, BH enabled
+ */
+bool lock_sock_fast(struct sock *sk)
+{
+       might_sleep();
+       spin_lock_bh(&sk->sk_lock.slock);
+
+       if (!sk->sk_lock.owned)
+               /*
+                * Note : We must disable BH
+                */
+               return false;
+
+       __lock_sock(sk);
+       sk->sk_lock.owned = 1;
+       spin_unlock(&sk->sk_lock.slock);
+       /*
+        * The sk_lock has mutex_lock() semantics here:
+        */
+       mutex_acquire(&sk->sk_lock.dep_map, 0, 0, _RET_IP_);
+       local_bh_enable();
+       return true;
+}
+EXPORT_SYMBOL(lock_sock_fast);
+
 int sock_get_timestamp(struct sock *sk, struct timeval __user *userstamp)
 {
        struct timeval tv;