af_vsock: separate wait data loop
authorArseny Krasnov <arseny.krasnov@kaspersky.com>
Fri, 11 Jun 2021 11:10:07 +0000 (14:10 +0300)
committerDavid S. Miller <davem@davemloft.net>
Fri, 11 Jun 2021 20:32:46 +0000 (13:32 -0700)
Wait loop for data could be shared between SEQPACKET and STREAM
sockets, so move it to dedicated function. While moving the code
around, let's update an old comment.

Signed-off-by: Arseny Krasnov <arseny.krasnov@kaspersky.com>
Reviewed-by: Stefano Garzarella <sgarzare@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
net/vmw_vsock/af_vsock.c

index 7dd8e70..4269e80 100644 (file)
@@ -1833,6 +1833,69 @@ out:
        return err;
 }
 
+static int vsock_wait_data(struct sock *sk, struct wait_queue_entry *wait,
+                          long timeout,
+                          struct vsock_transport_recv_notify_data *recv_data,
+                          size_t target)
+{
+       const struct vsock_transport *transport;
+       struct vsock_sock *vsk;
+       s64 data;
+       int err;
+
+       vsk = vsock_sk(sk);
+       err = 0;
+       transport = vsk->transport;
+
+       while ((data = vsock_stream_has_data(vsk)) == 0) {
+               prepare_to_wait(sk_sleep(sk), wait, TASK_INTERRUPTIBLE);
+
+               if (sk->sk_err != 0 ||
+                   (sk->sk_shutdown & RCV_SHUTDOWN) ||
+                   (vsk->peer_shutdown & SEND_SHUTDOWN)) {
+                       break;
+               }
+
+               /* Don't wait for non-blocking sockets. */
+               if (timeout == 0) {
+                       err = -EAGAIN;
+                       break;
+               }
+
+               if (recv_data) {
+                       err = transport->notify_recv_pre_block(vsk, target, recv_data);
+                       if (err < 0)
+                               break;
+               }
+
+               release_sock(sk);
+               timeout = schedule_timeout(timeout);
+               lock_sock(sk);
+
+               if (signal_pending(current)) {
+                       err = sock_intr_errno(timeout);
+                       break;
+               } else if (timeout == 0) {
+                       err = -EAGAIN;
+                       break;
+               }
+       }
+
+       finish_wait(sk_sleep(sk), wait);
+
+       if (err)
+               return err;
+
+       /* Internal transport error when checking for available
+        * data. XXX This should be changed to a connection
+        * reset in a later change.
+        */
+       if (data < 0)
+               return -ENOMEM;
+
+       return data;
+}
+
 static int
 vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
                          int flags)
@@ -1912,85 +1975,34 @@ vsock_connectible_recvmsg(struct socket *sock, struct msghdr *msg, size_t len,
 
 
        while (1) {
-               s64 ready;
+               ssize_t read;
 
-               prepare_to_wait(sk_sleep(sk), &wait, TASK_INTERRUPTIBLE);
-               ready = vsock_stream_has_data(vsk);
+               err = vsock_wait_data(sk, &wait, timeout, &recv_data, target);
+               if (err <= 0)
+                       break;
 
-               if (ready == 0) {
-                       if (sk->sk_err != 0 ||
-                           (sk->sk_shutdown & RCV_SHUTDOWN) ||
-                           (vsk->peer_shutdown & SEND_SHUTDOWN)) {
-                               finish_wait(sk_sleep(sk), &wait);
-                               break;
-                       }
-                       /* Don't wait for non-blocking sockets. */
-                       if (timeout == 0) {
-                               err = -EAGAIN;
-                               finish_wait(sk_sleep(sk), &wait);
-                               break;
-                       }
-
-                       err = transport->notify_recv_pre_block(
-                                       vsk, target, &recv_data);
-                       if (err < 0) {
-                               finish_wait(sk_sleep(sk), &wait);
-                               break;
-                       }
-                       release_sock(sk);
-                       timeout = schedule_timeout(timeout);
-                       lock_sock(sk);
-
-                       if (signal_pending(current)) {
-                               err = sock_intr_errno(timeout);
-                               finish_wait(sk_sleep(sk), &wait);
-                               break;
-                       } else if (timeout == 0) {
-                               err = -EAGAIN;
-                               finish_wait(sk_sleep(sk), &wait);
-                               break;
-                       }
-               } else {
-                       ssize_t read;
-
-                       finish_wait(sk_sleep(sk), &wait);
-
-                       if (ready < 0) {
-                               /* Invalid queue pair content. XXX This should
-                               * be changed to a connection reset in a later
-                               * change.
-                               */
-
-                               err = -ENOMEM;
-                               goto out;
-                       }
-
-                       err = transport->notify_recv_pre_dequeue(
-                                       vsk, target, &recv_data);
-                       if (err < 0)
-                               break;
+               err = transport->notify_recv_pre_dequeue(vsk, target,
+                                                        &recv_data);
+               if (err < 0)
+                       break;
 
-                       read = transport->stream_dequeue(
-                                       vsk, msg,
-                                       len - copied, flags);
-                       if (read < 0) {
-                               err = -ENOMEM;
-                               break;
-                       }
+               read = transport->stream_dequeue(vsk, msg, len - copied, flags);
+               if (read < 0) {
+                       err = -ENOMEM;
+                       break;
+               }
 
-                       copied += read;
+               copied += read;
 
-                       err = transport->notify_recv_post_dequeue(
-                                       vsk, target, read,
-                                       !(flags & MSG_PEEK), &recv_data);
-                       if (err < 0)
-                               goto out;
+               err = transport->notify_recv_post_dequeue(vsk, target, read,
+                                               !(flags & MSG_PEEK), &recv_data);
+               if (err < 0)
+                       goto out;
 
-                       if (read >= target || flags & MSG_PEEK)
-                               break;
+               if (read >= target || flags & MSG_PEEK)
+                       break;
 
-                       target -= read;
-               }
+               target -= read;
        }
 
        if (sk->sk_err)