[PATCH net-next v5 2/5] vsock/virtio: factor RX skb metadata budget check

[Jia Jia <physicalmtea@gmail.com>]

Extract the skb metadata budget check from virtio_transport_inc_rx_pkt()
into virtio_transport_rx_buf_full().

The helper retains the existing condition and will be reused by a
following RX batching change.

Signed-off-by: Jia Jia <physicalmtea@gmail.com>
---
 net/vmw_vsock/virtio_transport_common.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/net/vmw_vsock/virtio_transport_common.c b/net/vmw_vsock/virtio_transport_common.c
index 43325d7aebbb1..2a9cfed085515 100644
--- a/net/vmw_vsock/virtio_transport_common.c
+++ b/net/vmw_vsock/virtio_transport_common.c
@@ -576,11 +576,17 @@ virtio_transport_collapse_rx_queue(struct virtio_vsock_sock *vvs,
 	skb_queue_splice(&new_queue, &vvs->rx_queue);
 }
 
-static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
-					u32 len)
+static bool
+virtio_transport_rx_buf_full(struct virtio_vsock_sock *vvs)
 {
 	u64 skb_overhead = (skb_queue_len(&vvs->rx_queue) + 1) * SKB_TRUESIZE(0);
 
+	return skb_overhead > vvs->buf_alloc;
+}
+
+static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
+					u32 len)
+{
 	/* Allow at most buf_alloc * 2 total budget (payload + overhead),
 	 * similar to how SO_RCVBUF is doubled to reserve space for sk_buff
 	 * metadata. Check payload against buf_alloc to be sure the other
@@ -588,7 +594,7 @@ static bool virtio_transport_inc_rx_pkt(struct virtio_vsock_sock *vvs,
 	 * queue growth.
 	 */
 	if ((u64)vvs->buf_used + len > vvs->buf_alloc ||
-	    skb_overhead > vvs->buf_alloc)
+	    virtio_transport_rx_buf_full(vvs))
 		return false;
 
 	vvs->rx_bytes += len;
-- 
2.53.0