hv_netvsc: synchronize netvsc_change_mtu()/netvsc_set_channels() with netvsc_remove()
When netvsc device is removed during mtu change or channels setup we get
into troubles as both paths are trying to remove the device. Synchronize
them with start_remove flag and rtnl lock.
Signed-off-by: Vitaly Kuznetsov <vkuznets@redhat.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 7325d69..6a69b5c 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -759,7 +759,7 @@
int ret = 0;
bool recovering = false;
- if (!nvdev || nvdev->destroy)
+ if (net_device_ctx->start_remove || !nvdev || nvdev->destroy)
return -ENODEV;
num_chn = nvdev->num_chn;
@@ -907,7 +907,7 @@
u32 num_chn;
int ret = 0;
- if (nvdev == NULL || nvdev->destroy)
+ if (ndevctx->start_remove || !nvdev || nvdev->destroy)
return -ENODEV;
if (nvdev->nvsp_version >= NVSP_PROTOCOL_VERSION_2)
@@ -1445,7 +1445,12 @@
ndev_ctx = netdev_priv(net);
net_device = ndev_ctx->nvdev;
+ /* Avoid racing with netvsc_change_mtu()/netvsc_set_channels()
+ * removing the device.
+ */
+ rtnl_lock();
ndev_ctx->start_remove = true;
+ rtnl_unlock();
cancel_delayed_work_sync(&ndev_ctx->dwork);
cancel_work_sync(&ndev_ctx->work);