trans: improve the error handling in fakeauth

Previously the node was not correctly torn down if adding the newly
created netnode to the hash table failed.  Fix this by rearranging the
code, doing the hash table modification first because it is easier to
undo.

* trans/fakeroot.c (new_node): Fix the error handling.

1 files changed, 20 insertions, 17 deletions

diff --git a/trans/fakeroot.c b/trans/fakeroot.c
index 5c4854d1..3756f489 100644
--- a/trans/fakeroot.c
+++ b/trans/fakeroot.c
@@ -95,28 +95,31 @@ new_node (file_t file, mach_port_t idport, int locked, int openmodes,
 	  return err;
 	}
     }
+
+  if (!locked)
+    pthread_mutex_lock (&idport_ihash_lock);
+  err = hurd_ihash_add (&idport_ihash, nn->idport, nn);
+  if (err)
+    goto lose;
+
   *np = nn->np = netfs_make_node (nn);
   if (*np == 0)
     {
-      if (locked)
-	pthread_mutex_unlock (&idport_ihash_lock);
       err = ENOMEM;
+      goto lose_hash;
     }
-  else
-    {
-      if (!locked)
-	pthread_mutex_lock (&idport_ihash_lock);
-      err = hurd_ihash_add (&idport_ihash, nn->idport, nn);
-      if (!err)
-	pthread_mutex_lock (&(*np)->lock);
-      pthread_mutex_unlock (&idport_ihash_lock);
-    }
-  if (err)
-    {
-      mach_port_deallocate (mach_task_self (), nn->idport);
-      mach_port_deallocate (mach_task_self (), file);
-      free (nn);
-    }
+
+  pthread_mutex_lock (&(*np)->lock);
+  pthread_mutex_unlock (&idport_ihash_lock);
+  return 0;
+
+ lose_hash:
+  hurd_ihash_locp_remove (&idport_ihash, nn->idport_locp);
+ lose:
+  pthread_mutex_unlock (&idport_ihash_lock);
+  mach_port_deallocate (mach_task_self (), nn->idport);
+  mach_port_deallocate (mach_task_self (), file);
+  free (nn);
   return err;
 }