@@ -47,12 +47,6 @@ struct scm_stat {
#define UNIXCB(skb) (*(struct unix_skb_parms *)&((skb)->cb))
-#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock)
-#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock)
-#define unix_state_lock_nested(s) \
- spin_lock_nested(&unix_sk(s)->lock, \
- SINGLE_DEPTH_NESTING)
-
/* The AF_UNIX socket */
struct unix_sock {
/* WARNING: sk has to be the first member */
@@ -80,6 +74,20 @@ static inline struct unix_sock *unix_sk(const struct sock *sk)
return (struct unix_sock *)sk;
}
+#define unix_state_lock(s) spin_lock(&unix_sk(s)->lock)
+#define unix_state_unlock(s) spin_unlock(&unix_sk(s)->lock)
+enum unix_socket_lock_class {
+ U_LOCK_NORMAL,
+ U_LOCK_SECOND, /* for double locking, see unix_state_double_lock(). */
+ U_LOCK_DIAG, /* used while dumping icons, see sk_diag_dump_icons(). */
+};
+
+static inline void unix_state_lock_nested(struct sock *sk,
+ enum unix_socket_lock_class subclass)
+{
+ spin_lock_nested(&unix_sk(sk)->lock, subclass);
+}
+
#define peer_wait peer_wq.wait
long unix_inq_len(struct sock *sk);
@@ -1192,13 +1192,11 @@ static void unix_state_double_lock(struct sock *sk1, struct sock *sk2)
unix_state_lock(sk1);
return;
}
- if (sk1 < sk2) {
- unix_state_lock(sk1);
- unix_state_lock_nested(sk2);
- } else {
- unix_state_lock(sk2);
- unix_state_lock_nested(sk1);
- }
+ if (sk1 > sk2)
+ swap(sk1, sk2);
+
+ unix_state_lock(sk1);
+ unix_state_lock_nested(sk2, U_LOCK_SECOND);
}
static void unix_state_double_unlock(struct sock *sk1, struct sock *sk2)
@@ -1426,7 +1424,7 @@ static int unix_stream_connect(struct socket *sock, struct sockaddr *uaddr,
goto out_unlock;
}
- unix_state_lock_nested(sk);
+ unix_state_lock_nested(sk, U_LOCK_SECOND);
if (sk->sk_state != st) {
unix_state_unlock(sk);
@@ -83,7 +83,7 @@ static int sk_diag_dump_icons(struct sock *sk, struct sk_buff *nlskb)
* queue lock. With the other's queue locked it's
* OK to lock the state.
*/
- unix_state_lock_nested(req);
+ unix_state_lock_nested(req, U_LOCK_DIAG);
peer = unix_sk(req)->peer;
buf[i++] = (peer ? sock_i_ino(peer) : 0);
unix_state_unlock(req);