[PATCH net-next v3 16/16] virtio_net: take the rtnl lock when calling virtnet_set_affinity

[Antoine Tenart]

netif_set_xps_queue must be called with the rtnl lock taken, and this is
now enforced using ASSERT_RTNL(). In virtio_net, netif_set_xps_queue is
called by virtnet_set_affinity. As this function can be called from an
ethtool helper, we can't take the rtnl lock directly in it. Instead we
take the rtnl lock when calling virtnet_set_affinity when the rtnl lock
isn't taken already.

Signed-off-by: Antoine Tenart <aten...@kernel.org>
---
 drivers/net/virtio_net.c | 6 ++++++
 1 file changed, 6 insertions(+)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index dde9bbcc5ff0..54d2277f6c98 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2027,7 +2027,9 @@ static int virtnet_cpu_online(unsigned int cpu, struct 
hlist_node *node)
 {
        struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
                                                   node);
+       rtnl_lock();
        virtnet_set_affinity(vi);
+       rtnl_unlock();
        return 0;
 }
 
@@ -2035,7 +2037,9 @@ static int virtnet_cpu_dead(unsigned int cpu, struct 
hlist_node *node)
 {
        struct virtnet_info *vi = hlist_entry_safe(node, struct virtnet_info,
                                                   node_dead);
+       rtnl_lock();
        virtnet_set_affinity(vi);
+       rtnl_unlock();
        return 0;
 }
 
@@ -2883,7 +2887,9 @@ static int init_vqs(struct virtnet_info *vi)
                goto err_free;
 
        get_online_cpus();
+       rtnl_lock();
        virtnet_set_affinity(vi);
+       rtnl_unlock();
        put_online_cpus();
 
        return 0;
-- 
2.29.2