AF_UNIX: Fix poll blocking problem when reading from a stream socket

poll() call may be blocked by concurrent reading from the same stream
socket.

Signed-off-by: Alexey Moiseytsev <himeraster@gmail.com>
Acked-by: Eric Dumazet <eric.dumazet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index 466fbcc..b595a3d 100644 (file)
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -1957,6 +1957,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
                        if ((UNIXCB(skb).pid  != siocb->scm->pid) ||
                            (UNIXCB(skb).cred != siocb->scm->cred)) {
                                skb_queue_head(&sk->sk_receive_queue, skb);
+                               sk->sk_data_ready(sk, skb->len);
                                break;
                        }
                } else {
@@ -1974,6 +1975,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
                chunk = min_t(unsigned int, skb->len, size);
                if (memcpy_toiovec(msg->msg_iov, skb->data, chunk)) {
                        skb_queue_head(&sk->sk_receive_queue, skb);
+                       sk->sk_data_ready(sk, skb->len);
                        if (copied == 0)
                                copied = -EFAULT;
                        break;
@@ -1991,6 +1993,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
                        /* put the skb back if we didn't use it up.. */
                        if (skb->len) {
                                skb_queue_head(&sk->sk_receive_queue, skb);
+                               sk->sk_data_ready(sk, skb->len);
                                break;
                        }
 
@@ -2006,6 +2009,7 @@ static int unix_stream_recvmsg(struct kiocb *iocb, struct socket *sock,
 
                        /* put message back and return */
                        skb_queue_head(&sk->sk_receive_queue, skb);
+                       sk->sk_data_ready(sk, skb->len);
                        break;
                }
        } while (size);