Re: [PATCH v3 2/5] vsock/virtio: fix locking for fwd_cnt and buf_alloc

From: Stefano Garzarella
Date: Mon Jun 03 2019 - 07:11:09 EST


On Sun, Jun 02, 2019 at 06:03:34PM -0700, David Miller wrote:
> From: Stefano Garzarella <sgarzare@xxxxxxxxxx>
> Date: Fri, 31 May 2019 15:39:51 +0200
>
> > @@ -434,7 +434,9 @@ void virtio_transport_set_buffer_size(struct vsock_sock *vsk, u64 val)
> > if (val > vvs->buf_size_max)
> > vvs->buf_size_max = val;
> > vvs->buf_size = val;
> > + spin_lock_bh(&vvs->rx_lock);
> > vvs->buf_alloc = val;
> > + spin_unlock_bh(&vvs->rx_lock);
>
> This locking doesn't do anything other than to strongly order the
> buf_size store to occur before the buf_alloc one.

Sure, I'll remove the lock. I was confused because I moved its reading
under the rx_lock (together with other variables), but here I'm updating
only buf_alloc, so this lock is useless.

Thanks,
Stefano