1 files changed, 71 insertions, 16 deletions

diff --git a/net/unix/af_unix.c b/net/unix/af_unix.c
index e18cd3628db4..015606b54d9b 100644
--- a/net/unix/af_unix.c
+++ b/net/unix/af_unix.c
@@ -8,8 +8,6 @@
  *              as published by the Free Software Foundation; either version
  *              2 of the License, or (at your option) any later version.
  *
- * Version:     $Id: af_unix.c,v 1.133 2002/02/08 03:57:19 davem Exp $
- *
  * Fixes:
  *              Linus Torvalds  :       Assorted bug cures.
  *              Niibe Yutaka    :       async I/O support.
@@ -169,6 +167,11 @@ static inline int unix_may_send(struct sock *sk, struct sock *osk)
         return (unix_peer(osk) == NULL || unix_our_peer(sk, osk));
 }
 
+static inline int unix_recvq_full(struct sock const *sk)
+{
+        return skb_queue_len(&sk->sk_receive_queue) > sk->sk_max_ack_backlog;
+}
+
 static struct sock *unix_peer_get(struct sock *s)
 {
         struct sock *peer;
@@ -224,7 +227,7 @@ static void __unix_remove_socket(struct sock *sk)
 
 static void __unix_insert_socket(struct hlist_head *list, struct sock *sk)
 {
-        BUG_TRAP(sk_unhashed(sk));
+        WARN_ON(!sk_unhashed(sk));
         sk_add_node(sk, list);
 }
 
@@ -347,9 +350,9 @@ static void unix_sock_destructor(struct sock *sk)
 
         skb_queue_purge(&sk->sk_receive_queue);
 
-        BUG_TRAP(!atomic_read(&sk->sk_wmem_alloc));
-        BUG_TRAP(sk_unhashed(sk));
-        BUG_TRAP(!sk->sk_socket);
+        WARN_ON(atomic_read(&sk->sk_wmem_alloc));
+        WARN_ON(!sk_unhashed(sk));
+        WARN_ON(sk->sk_socket);
         if (!sock_flag(sk, SOCK_DEAD)) {
                 printk("Attempt to release alive unix socket: %p\n", sk);
                 return;
@@ -482,6 +485,8 @@ static int unix_socketpair(struct socket *, struct socket *);
 static int unix_accept(struct socket *, struct socket *, int);
 static int unix_getname(struct socket *, struct sockaddr *, int *, int);
 static unsigned int unix_poll(struct file *, struct socket *, poll_table *);
+static unsigned int unix_dgram_poll(struct file *, struct socket *,
+                                    poll_table *);
 static int unix_ioctl(struct socket *, unsigned int, unsigned long);
 static int unix_shutdown(struct socket *, int);
 static int unix_stream_sendmsg(struct kiocb *, struct socket *,
@@ -527,7 +532,7 @@ static const struct proto_ops unix_dgram_ops = {
         .socketpair =   unix_socketpair,
         .accept =       sock_no_accept,
         .getname =      unix_getname,
-        .poll =         datagram_poll,
+        .poll =         unix_dgram_poll,
         .ioctl =        unix_ioctl,
         .listen =       sock_no_listen,
         .shutdown =     unix_shutdown,
@@ -548,7 +553,7 @@ static const struct proto_ops unix_seqpacket_ops = {
         .socketpair =   unix_socketpair,
         .accept =       unix_accept,
         .getname =      unix_getname,
-        .poll =         datagram_poll,
+        .poll =         unix_dgram_poll,
         .ioctl =        unix_ioctl,
         .listen =       unix_listen,
         .shutdown =     unix_shutdown,
@@ -598,7 +603,7 @@ static struct sock * unix_create1(struct net *net, struct socket *sock)
         u->dentry = NULL;
         u->mnt    = NULL;
         spin_lock_init(&u->lock);
-        atomic_set(&u->inflight, 0);
+        atomic_long_set(&u->inflight, 0);
         INIT_LIST_HEAD(&u->link);
         mutex_init(&u->readlock); /* single task reading lock */
         init_waitqueue_head(&u->peer_wait);
@@ -983,8 +988,7 @@ static long unix_wait_for_peer(struct sock *other, long timeo)
 
         sched = !sock_flag(other, SOCK_DEAD) &&
                 !(other->sk_shutdown & RCV_SHUTDOWN) &&
-                (skb_queue_len(&other->sk_receive_queue) >
-                 other->sk_max_ack_backlog);
+                unix_recvq_full(other);
 
         unix_state_unlock(other);
 
@@ -1058,8 +1062,7 @@ restart:
         if (other->sk_state != TCP_LISTEN)
                 goto out_unlock;
 
-        if (skb_queue_len(&other->sk_receive_queue) >
-            other->sk_max_ack_backlog) {
+        if (unix_recvq_full(other)) {
                 err = -EAGAIN;
                 if (!timeo)
                         goto out_unlock;
@@ -1428,9 +1431,7 @@ restart:
                         goto out_unlock;
         }
 
-        if (unix_peer(other) != sk &&
-            (skb_queue_len(&other->sk_receive_queue) >
-             other->sk_max_ack_backlog)) {
+        if (unix_peer(other) != sk && unix_recvq_full(other)) {
                 if (!timeo) {
                         err = -EAGAIN;
                         goto out_unlock;
@@ -1991,6 +1992,60 @@ static unsigned int unix_poll(struct file * file, struct socket *sock, poll_tabl
         return mask;
 }
 
+static unsigned int unix_dgram_poll(struct file *file, struct socket *sock,
+                                    poll_table *wait)
+{
+        struct sock *sk = sock->sk, *other;
+        unsigned int mask, writable;
+
+        poll_wait(file, sk->sk_sleep, wait);
+        mask = 0;
+
+        /* exceptional events? */
+        if (sk->sk_err || !skb_queue_empty(&sk->sk_error_queue))
+                mask |= POLLERR;
+        if (sk->sk_shutdown & RCV_SHUTDOWN)
+                mask |= POLLRDHUP;
+        if (sk->sk_shutdown == SHUTDOWN_MASK)
+                mask |= POLLHUP;
+
+        /* readable? */
+        if (!skb_queue_empty(&sk->sk_receive_queue) ||
+            (sk->sk_shutdown & RCV_SHUTDOWN))
+                mask |= POLLIN | POLLRDNORM;
+
+        /* Connection-based need to check for termination and startup */
+        if (sk->sk_type == SOCK_SEQPACKET) {
+                if (sk->sk_state == TCP_CLOSE)
+                        mask |= POLLHUP;
+                /* connection hasn't started yet? */
+                if (sk->sk_state == TCP_SYN_SENT)
+                        return mask;
+        }
+
+        /* writable? */
+        writable = unix_writable(sk);
+        if (writable) {
+                other = unix_peer_get(sk);
+                if (other) {
+                        if (unix_peer(other) != sk) {
+                                poll_wait(file, &unix_sk(other)->peer_wait,
+                                          wait);
+                                if (unix_recvq_full(other))
+                                        writable = 0;
+                        }
+
+                        sock_put(other);
+                }
+        }
+
+        if (writable)
+                mask |= POLLOUT | POLLWRNORM | POLLWRBAND;
+        else
+                set_bit(SOCK_ASYNC_NOSPACE, &sk->sk_socket->flags);
+
+        return mask;
+}
 
 #ifdef CONFIG_PROC_FS
 static struct sock *first_unix_socket(int *i)