[PATCH] revert async probing of VMBus network devices.

[PATCH] revert async probing of VMBus network devices.

[Stephen Hemminger]

Doing asynchronous probing can lead to reordered network device names.
And because udev doesn't have any useful information to construct a
persistent name, this causes VM's to sporadically boot with reordered
device names and no connectivity.

This shows up on the Ubuntu image on larger VM's where 30% of the
time eth0 and eth1 get swapped.

Note: udev MAC address policy is disabled on Azure images
because the netvsc and PCI VF will have the same mac address.

Fixes: af0a5646cb8d ("use the new async probing feature for the hyperv drivers")
Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
---
 drivers/net/hyperv/netvsc_drv.c | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
index 06393b215102..1a2c32111106 100644
--- a/drivers/net/hyperv/netvsc_drv.c
+++ b/drivers/net/hyperv/netvsc_drv.c
@@ -2411,9 +2411,6 @@ static struct  hv_driver netvsc_drv = {
 	.id_table = id_table,
 	.probe = netvsc_probe,
 	.remove = netvsc_remove,
-	.driver = {
-		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
-	},
 };
 
 /*
-- 
2.20.1

RE: [PATCH] revert async probing of VMBus network devices.

[Haiyang Zhang]

> -----Original Message-----
> From: linux-hyperv-owner@vger.kernel.org <linux-hyperv-
> owner@vger.kernel.org> On Behalf Of Stephen Hemminger
> Sent: Wednesday, June 5, 2019 2:51 PM
> To: netdev@vger.kernel.org
> Cc: linux-hyperv@vger.kernel.org; Stephen Hemminger
> <sthemmin@microsoft.com>
> Subject: [PATCH] revert async probing of VMBus network devices.
> 
> Doing asynchronous probing can lead to reordered network device names.
> And because udev doesn't have any useful information to construct a
> persistent name, this causes VM's to sporadically boot with reordered device
> names and no connectivity.
> 
> This shows up on the Ubuntu image on larger VM's where 30% of the time
> eth0 and eth1 get swapped.
> 
> Note: udev MAC address policy is disabled on Azure images because the
> netvsc and PCI VF will have the same mac address.
> 
> Fixes: af0a5646cb8d ("use the new async probing feature for the hyperv
> drivers")
> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> ---

Reviewed-by: Haiyang Zhang <haiyangz@microsoft.com>

Re: [PATCH] revert async probing of VMBus network devices.

[Stephen Hemminger]

On Wed,  5 Jun 2019 11:51:14 -0700
Stephen Hemminger <stephen@networkplumber.org> wrote:

> Doing asynchronous probing can lead to reordered network device names.
> And because udev doesn't have any useful information to construct a
> persistent name, this causes VM's to sporadically boot with reordered
> device names and no connectivity.
> 
> This shows up on the Ubuntu image on larger VM's where 30% of the
> time eth0 and eth1 get swapped.
> 
> Note: udev MAC address policy is disabled on Azure images
> because the netvsc and PCI VF will have the same mac address.
> 
> Fixes: af0a5646cb8d ("use the new async probing feature for the hyperv drivers")
> Signed-off-by: Stephen Hemminger <sthemmin@microsoft.com>
> ---
>  drivers/net/hyperv/netvsc_drv.c | 3 ---
>  1 file changed, 3 deletions(-)
> 
> diff --git a/drivers/net/hyperv/netvsc_drv.c b/drivers/net/hyperv/netvsc_drv.c
> index 06393b215102..1a2c32111106 100644
> --- a/drivers/net/hyperv/netvsc_drv.c
> +++ b/drivers/net/hyperv/netvsc_drv.c
> @@ -2411,9 +2411,6 @@ static struct  hv_driver netvsc_drv = {
>  	.id_table = id_table,
>  	.probe = netvsc_probe,
>  	.remove = netvsc_remove,
> -	.driver = {
> -		.probe_type = PROBE_PREFER_ASYNCHRONOUS,
> -	},
>  };
>  
>  /*

Even though storage can handle out of order devices, networking can not.
The network devices in Hyper-V do not have any persistant properties that will
work with existing udev. The current kernel is breaking current distributions.
This patch fixes it, why did you reject it?