Re: [PATCH v3 2/5] vsock/virtio: fix locking for fwd_cnt and buf_alloc
From: David Miller <davem@davemloft.net>
Date: 2019-06-03 01:03:37
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From: Stefano Garzarella <sgarzare@redhat.com> Date: Fri, 31 May 2019 15:39:51 +0200
quoted hunk ↗ jump to hunk
@@ -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. If you need a memory barrier, use one.