netdev: Correctly maintain netdev refcounts even if errors occur.

If an error occured while opening a netdev it would decrement the
refcount, even though it was never incremented.  Depending on
the timing this could result in either an error message or an
assertion failure.  This workaround simply always increments
the refcount before openning a device.  A more complete fix
already exists in the netdev overhaul in the 'next' branch.

NIC-59

diff --git a/lib/netdev.c b/lib/netdev.c
index 804050fcdc978c87ab96f1e0918d4bd9cb8297d3..f1eb29b521fa83022e706c34e27b69cef2c48be0 100644 (file)
--- a/lib/netdev.c
+++ b/lib/netdev.c
@@ -235,6 +235,7 @@ netdev_open(const char *name, int ethertype, struct netdev **netdevp)
 
     netdev_obj = shash_find_data(&netdev_obj_shash, name);
     if (netdev_obj) {
+        netdev_obj->ref_cnt++;
         error = netdev_obj->netdev_class->open(name, ethertype, &netdev);
     } else {
         /* Default to "system". */
@@ -249,16 +250,14 @@ netdev_open(const char *name, int ethertype, struct netdev **netdevp)
                  * closes its handle. */
                 error = class->create(name, "system", &empty_args, false);
                 if (!error) {
-                    error = class->open(name, ethertype, &netdev);
                     netdev_obj = shash_find_data(&netdev_obj_shash, name);
+                    netdev_obj->ref_cnt++;
+                    error = class->open(name, ethertype, &netdev);
                 }
                 break;
             }
         }
     }
-    if (!error) {
-        netdev_obj->ref_cnt++;
-    }
 
     *netdevp = error ? NULL : netdev;
     return error;