1 files changed, 20 insertions, 15 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 502e572af3fd..1c3c1f3a3ec4 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -2078,8 +2078,8 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
         struct scm_cookie scm;
         struct sock *sk = sock->sk;
         struct unix_sock *u = unix_sk(sk);
-        int noblock = flags & MSG_DONTWAIT;
-        struct sk_buff *skb;
+        struct sk_buff *skb, *last;
+        long timeo;
         int err;
         int peeked, skip;
 
@@ -2087,26 +2087,32 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
         if (flags&MSG_OOB)
                 goto out;
 
-        err = mutex_lock_interruptible(&u->readlock);
-        if (unlikely(err)) {
-                /* recvmsg() in non blocking mode is supposed to return -EAGAIN
-                 * sk_rcvtimeo is not honored by mutex_lock_interruptible()
-                 */
-                err = noblock ? -EAGAIN : -ERESTARTSYS;
-                goto out;
-        }
+        timeo = sock_rcvtimeo(sk, flags & MSG_DONTWAIT);
 
-        skip = sk_peek_offset(sk, flags);
+        do {
+                mutex_lock(&u->readlock);
 
-        skb = __skb_recv_datagram(sk, flags, &peeked, &skip, &err);
-        if (!skb) {
+                skip = sk_peek_offset(sk, flags);
+                skb = __skb_try_recv_datagram(sk, flags, &peeked, &skip, &err,
+                                              &last);
+                if (skb)
+                        break;
+
+                mutex_unlock(&u->readlock);
+
+                if (err != -EAGAIN)
+                        break;
+        } while (timeo &&
+                 !__skb_wait_for_more_packets(sk, &err, &timeo, last));
+
+        if (!skb) { /* implies readlock unlocked */
                 unix_state_lock(sk);
                 /* Signal EOF on disconnected non-blocking SEQPACKET socket. */
                 if (sk->sk_type == SOCK_SEQPACKET && err == -EAGAIN &&
                     (sk->sk_shutdown & RCV_SHUTDOWN))
                         err = 0;
                 unix_state_unlock(sk);
-                goto out_unlock;
+                goto out;
         }
 
         if (wq_has_sleeper(&u->peer_wait))
@@ -2164,7 +2170,6 @@ static int unix_dgram_recvmsg(struct socket *sock, struct msghdr *msg,
 
 out_free:
         skb_free_datagram(sk, skb);
-out_unlock:
         mutex_unlock(&u->readlock);
 out:
         return err;