IPoIB: Use rtnl lock/unlock when changing device flags

Use of this lock is required to synchronize changes to the netdvice's
data structs.  Also move the call to ipoib_flush_paths() after the
modification of the netdevice flags in set_mode().

Signed-off-by: Eli Cohen <eli@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

2 files changed, 10 insertions, 3 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_cm.c b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
index 37bf67b2a26f..b4269139135b 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_cm.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_cm.c
@@ -1440,7 +1440,9 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr,
                 ipoib_warn(priv, "enabling connected mode "
                            "will cause multicast packet drops\n");
 
+                rtnl_lock();
                 dev->features &= ~(NETIF_F_IP_CSUM | NETIF_F_SG | NETIF_F_TSO);
+                rtnl_unlock();
                 priv->tx_wr.send_flags &= ~IB_SEND_IP_CSUM;
 
                 ipoib_flush_paths(dev);
@@ -1449,14 +1451,16 @@ static ssize_t set_mode(struct device *d, struct device_attribute *attr,
 
         if (!strcmp(buf, "datagram\n")) {
                 clear_bit(IPOIB_FLAG_ADMIN_CM, &priv->flags);
-                dev->mtu = min(priv->mcast_mtu, dev->mtu);
-                ipoib_flush_paths(dev);
 
+                rtnl_lock();
                 if (test_bit(IPOIB_FLAG_CSUM, &priv->flags)) {
                         dev->features |= NETIF_F_IP_CSUM | NETIF_F_SG;
                         if (priv->hca_caps & IB_DEVICE_UD_TSO)
                                 dev->features |= NETIF_F_TSO;
                 }
+                dev->mtu = min(priv->mcast_mtu, dev->mtu);
+                rtnl_unlock();
+                ipoib_flush_paths(dev);
 
                 return count;
         }
diff --git a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
index 71add7a8d53c..be1ed38cdcfd 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_multicast.c
@@ -575,8 +575,11 @@ void ipoib_mcast_join_task(struct work_struct *work)
 
         priv->mcast_mtu = IPOIB_UD_MTU(ib_mtu_enum_to_int(priv->broadcast->mcmember.mtu));
 
-        if (!ipoib_cm_admin_enabled(dev))
+        if (!ipoib_cm_admin_enabled(dev)) {
+                rtnl_lock();
                 dev->mtu = min(priv->mcast_mtu, priv->admin_mtu);
+                rtnl_unlock();
+        }
 
         ipoib_dbg_mcast(priv, "successfully joined all multicast groups\n");