From: Bobby Eshleman <bobby.eshleman@bytedance.com>

This saves original behaviour from af_vsock.c - switch any error
code returned from transport layer to ENOMEM.

Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
---
 net/vmw_vsock/hyperv_transport.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
index 59c3e2697069..fbbe55133da2 100644
--- a/net/vmw_vsock/hyperv_transport.c
+++ b/net/vmw_vsock/hyperv_transport.c
@@ -687,7 +687,7 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
 	if (bytes_written)
 		ret = bytes_written;
 	kfree(send_buf);
-	return ret;
+	return ret < 0 ? -ENOMEM : ret;
 }
 
 static s64 hvs_stream_has_data(struct vsock_sock *vsk)
-- 
2.25.1

On Fri, Nov 25, 2022 at 05:05:53PM +0000, Arseniy Krasnov wrote:
>From: Bobby Eshleman <bobby.eshleman@bytedance.com>
>
>This saves original behaviour from af_vsock.c - switch any error
>code returned from transport layer to ENOMEM.
>
>Signed-off-by: Bobby Eshleman <bobby.eshleman@bytedance.com>
>Signed-off-by: Arseniy Krasnov <AVKrasnov@sberdevices.ru>
>---
> net/vmw_vsock/hyperv_transport.c | 2 +-
> 1 file changed, 1 insertion(+), 1 deletion(-)
>
>diff --git a/net/vmw_vsock/hyperv_transport.c b/net/vmw_vsock/hyperv_transport.c
>index 59c3e2697069..fbbe55133da2 100644
>--- a/net/vmw_vsock/hyperv_transport.c
>+++ b/net/vmw_vsock/hyperv_transport.c
>@@ -687,7 +687,7 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock *vsk, struct msghdr *msg,
> 	if (bytes_written)
> 		ret = bytes_written;
> 	kfree(send_buf);
>-	return ret;
>+	return ret < 0 ? -ENOMEM : ret;

I'm not sure for hyperv we want to preserve -ENOMEM. This transport was 
added after virtio-vsock, so I think we can return the error directly.

@Dexuan what do you think?

Thanks,
Stefano

> From: Stefano Garzarella <sgarzare@redhat.com>
> Sent: Thursday, December 1, 2022 1:24 AM
> > [...]
> >--- a/net/vmw_vsock/hyperv_transport.c
> >+++ b/net/vmw_vsock/hyperv_transport.c
> >@@ -687,7 +687,7 @@ static ssize_t hvs_stream_enqueue(struct vsock_sock
> *vsk, struct msghdr *msg,
> > 	if (bytes_written)
> > 		ret = bytes_written;
> > 	kfree(send_buf);
> >-	return ret;
> >+	return ret < 0 ? -ENOMEM : ret;
> 
> I'm not sure for hyperv we want to preserve -ENOMEM. This transport was
> added after virtio-vsock, so I think we can return the error directly.
> 
> @Dexuan what do you think?
> 
> Thanks,
> Stefano

I also think we can return the error directly.
BTW, I doubt any user really depends on the value of a non-zero error code.