[PATCH v11 02/18] af_vsock: separate wait data loop

Arseny Krasnov
2021-06-11T11:10:24Z

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>
---
net/vmw_vsock/af_vsock.c | 156 +++++++++++++++++++++------------------
1 file changed, 84 insertions(+), 72 deletions(-)

diff --git a/net/vmw_vsock/af_vsock.c b/net/vmw_vsock/af_vsock.c
index 7dd8e70d78cd..4269e80b02cd 100644
--- a/net/vmw_vsock/af_vsock.c
+++ b/net/vmw_vsock/af_vsock.c
@@ -1833,6 +1833,69 @@ static int vsock_connectible_sendmsg(struct socket *sock, struct msghdr *msg,
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)
--
2.25.1