IPoIB: Free ipoib neigh on path record failure so path rec queries are retried

If IPoIB fails to look up a path record (eg if it tries during an SM
failover when one SM is dead but the new one hasn't taken over yet), the
driver ends up with a neighbour structure but no address handle (AH).
There's no mechanism to recover from this: any further packets sent to
this destination will be silently dumped in ipoib_start_xmit().

Fix this by freeing the neighbour structures when a path rec query
fails, so that the next packet queued to be sent will trigger a new path
record query.

Signed-off-by: Roland Dreier <roland@purestorage.com>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/infiniband/ulp/ipoib/ipoib_main.c b/drivers/infiniband/ulp/ipoib/ipoib_main.c
index 66d6da90982f..8534afd04e7c 100644
--- a/drivers/infiniband/ulp/ipoib/ipoib_main.c
+++ b/drivers/infiniband/ulp/ipoib/ipoib_main.c
@@ -510,6 +510,9 @@ static void path_rec_completion(int status,
 
         spin_unlock_irqrestore(&priv->lock, flags);
 
+        if (IS_ERR_OR_NULL(ah))
+                ipoib_del_neighs_by_gid(dev, path->pathrec.dgid.raw);
+
         if (old_ah)
                 ipoib_put_ah(old_ah);