[PATCH 0/2] xen-netfront: Fix issues with commit f599c64fdf7d

[PATCH 0/2] xen-netfront: Fix issues with commit f599c64fdf7d

[Ross Lagerwall]

Fix a couple of issues with commit f599c64fdf7d ("xen-netfront: Fix race
between device setup and open").

Ross Lagerwall (2):
  xen-netfront: Fix mismatched rtnl_unlock
  xen-netfront: Update features after registering netdev

 drivers/net/xen-netfront.c | 11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

-- 
2.9.5

[PATCH 1/2] xen-netfront: Fix mismatched rtnl_unlock

[Ross Lagerwall]

Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
---
 drivers/net/xen-netfront.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index 922ce0a..ee4cb6c 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1810,7 +1810,7 @@ static int talk_to_netback(struct xenbus_device *dev,
 	err = xen_net_read_mac(dev, info->netdev->dev_addr);
 	if (err) {
 		xenbus_dev_fatal(dev, err, "parsing %s/mac", dev->nodename);
-		goto out;
+		goto out_unlocked;
 	}
 
 	rtnl_lock();
@@ -1925,6 +1925,7 @@ static int talk_to_netback(struct xenbus_device *dev,
 	xennet_destroy_queues(info);
  out:
 	rtnl_unlock();
+out_unlocked:
 	device_unregister(&dev->dev);
 	return err;
 }
-- 
2.9.5

Re: [PATCH 1/2] xen-netfront: Fix mismatched rtnl_unlock

[Juergen Gross]

On 21/06/18 15:00, Ross Lagerwall wrote:
> Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
> Reported-by: Ben Hutchings <ben.hutchings@codethink.co.uk>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

[PATCH 2/2] xen-netfront: Update features after registering netdev

[Ross Lagerwall]

Update the features after calling register_netdev() otherwise the
device features are not set up correctly and it not possible to change
the MTU of the device. After this change, the features reported by
ethtool match the device's features before the commit which introduced
the issue and it is possible to change the device's MTU.

Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
Reported-by: Liam Shepherd <liam@dancer.es>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>
---
 drivers/net/xen-netfront.c | 8 ++++----
 1 file changed, 4 insertions(+), 4 deletions(-)

diff --git a/drivers/net/xen-netfront.c b/drivers/net/xen-netfront.c
index ee4cb6c..a57daec 100644
--- a/drivers/net/xen-netfront.c
+++ b/drivers/net/xen-netfront.c
@@ -1951,10 +1951,6 @@ static int xennet_connect(struct net_device *dev)
 	/* talk_to_netback() sets the correct number of queues */
 	num_queues = dev->real_num_tx_queues;
 
-	rtnl_lock();
-	netdev_update_features(dev);
-	rtnl_unlock();
-
 	if (dev->reg_state == NETREG_UNINITIALIZED) {
 		err = register_netdev(dev);
 		if (err) {
@@ -1964,6 +1960,10 @@ static int xennet_connect(struct net_device *dev)
 		}
 	}
 
+	rtnl_lock();
+	netdev_update_features(dev);
+	rtnl_unlock();
+
 	/*
 	 * All public and private state should now be sane.  Get
 	 * ready to start sending and receiving packets and give the driver
-- 
2.9.5

Re: [PATCH 2/2] xen-netfront: Update features after registering netdev

[Juergen Gross]

On 21/06/18 15:00, Ross Lagerwall wrote:
> Update the features after calling register_netdev() otherwise the
> device features are not set up correctly and it not possible to change
> the MTU of the device. After this change, the features reported by
> ethtool match the device's features before the commit which introduced
> the issue and it is possible to change the device's MTU.
> 
> Fixes: f599c64fdf7d ("xen-netfront: Fix race between device setup and open")
> Reported-by: Liam Shepherd <liam@dancer.es>
> Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>

Reviewed-by: Juergen Gross <jgross@suse.com>


Juergen

Re: [PATCH 0/2] xen-netfront: Fix issues with commit f599c64fdf7d

[David Miller]

From: Ross Lagerwall <ross.lagerwall@citrix.com>
Date: Thu, 21 Jun 2018 14:00:19 +0100

> Fix a couple of issues with commit f599c64fdf7d ("xen-netfront: Fix race
> between device setup and open").

Series applied and queued up for -stable.