vfio: Ignore sprurious notifies

Remove debugging WARN_ON if we get a spurious notify for a group that
no longer exists.  No reports of anyone hitting this, but it would
likely be a race and not a bug if they did.

Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

diff --git a/drivers/vfio/vfio.c b/drivers/vfio/vfio.c
index 6d18c3c..842f450 100644 (file)
--- a/drivers/vfio/vfio.c
+++ b/drivers/vfio/vfio.c
@@ -510,13 +510,11 @@ static int vfio_iommu_group_notifier(struct notifier_block *nb,
        struct device *dev = data;
 
        /*
-        * Need to go through a group_lock lookup to get a reference or
-        * we risk racing a group being removed.  Leave a WARN_ON for
-        * debuging, but if the group no longer exists, a spurious notify
-        * is harmless.
+        * Need to go through a group_lock lookup to get a reference or we
+        * risk racing a group being removed.  Ignore spurious notifies.
         */
        group = vfio_group_try_get(group);
-       if (WARN_ON(!group))
+       if (!group)
                return NOTIFY_OK;
 
        switch (action) {