IPoIB: Move ipoib_ib_dev_flush() to ipoib workqueue

Move ipoib_ib_dev_flush() to ipoib's workqueue.  This keeps it ordered
with respect to other work scheduled by the ipoib driver.  This fixes
problems with races, for example:
 - ipoib_ib_dev_flush() has started running because of an IB event
 - user does ifconfig ib0 down
 - ipoib_mcast_stop_thread() gets called twice and waits for the same
   completion twice

Signed-off-by: Jack Morgenstein <jackm@mellanox.co.il>
Signed-off-by: Michael S. Tsirkin <mst@mellanox.co.il>
Signed-off-by: Roland Dreier <rolandd@cisco.com>

1 files changed, 5 insertions, 4 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_ib.c b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
index 5a5367d10875..a1f5a05f2f36 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_ib.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_ib.c
@@ -435,7 +435,7 @@ int ipoib_ib_dev_up(struct net_device *dev)
         return ipoib_mcast_start_thread(dev);
 }
 
-int ipoib_ib_dev_down(struct net_device *dev)
+int ipoib_ib_dev_down(struct net_device *dev, int flush)
 {
         struct ipoib_dev_priv *priv = netdev_priv(dev);
 
@@ -450,10 +450,11 @@ int ipoib_ib_dev_down(struct net_device *dev)
                 set_bit(IPOIB_PKEY_STOP, &priv->flags);
                 cancel_delayed_work(&priv->pkey_task);
                 mutex_unlock(&pkey_mutex);
-                flush_workqueue(ipoib_workqueue);
+                if (flush)
+                        flush_workqueue(ipoib_workqueue);
         }
 
-        ipoib_mcast_stop_thread(dev, 1);
+        ipoib_mcast_stop_thread(dev, flush);
         ipoib_mcast_dev_flush(dev);
 
         ipoib_flush_paths(dev);
@@ -591,7 +592,7 @@ void ipoib_ib_dev_flush(void *_dev)
 
         ipoib_dbg(priv, "flushing\n");
 
-        ipoib_ib_dev_down(dev);
+        ipoib_ib_dev_down(dev, 0);
 
         /*
          * The device could have been brought down between the start and when