[PATCH] batman-adv: Less function calls in batadv_is_ap_isolated() after error detection

[SF Markus Elfring]

From: Markus Elfring <elfr...@users.sourceforge.net>
Date: Fri, 11 Mar 2016 13:10:20 +0100

The variables "tt_local_entry" and "tt_global_entry" were eventually
checked again despite of a corresponding null pointer test before.

* Avoid this double check by reordering a function call sequence
  and the better selection of jump targets.

* Omit the initialisation for these variables at the beginning then.

Signed-off-by: Markus Elfring <elfr...@users.sourceforge.net>
---
 net/batman-adv/translation-table.c | 25 +++++++++++--------------
 1 file changed, 11 insertions(+), 14 deletions(-)

diff --git a/net/batman-adv/translation-table.c 
b/net/batman-adv/translation-table.c
index 0b43e86..9c0193ee 100644
--- a/net/batman-adv/translation-table.c
+++ b/net/batman-adv/translation-table.c
@@ -3403,8 +3403,8 @@ void batadv_tt_local_commit_changes(struct batadv_priv 
*bat_priv)
 bool batadv_is_ap_isolated(struct batadv_priv *bat_priv, u8 *src, u8 *dst,
                           unsigned short vid)
 {
-       struct batadv_tt_local_entry *tt_local_entry = NULL;
-       struct batadv_tt_global_entry *tt_global_entry = NULL;
+       struct batadv_tt_local_entry *tt_local_entry;
+       struct batadv_tt_global_entry *tt_global_entry;
        struct batadv_softif_vlan *vlan;
        bool ret = false;
 
@@ -3413,27 +3413,24 @@ bool batadv_is_ap_isolated(struct batadv_priv 
*bat_priv, u8 *src, u8 *dst,
                return false;
 
        if (!atomic_read(&vlan->ap_isolation))
-               goto out;
+               goto vlan_put;
 
        tt_local_entry = batadv_tt_local_hash_find(bat_priv, dst, vid);
        if (!tt_local_entry)
-               goto out;
+               goto vlan_put;
 
        tt_global_entry = batadv_tt_global_hash_find(bat_priv, src, vid);
        if (!tt_global_entry)
-               goto out;
-
-       if (!_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
-               goto out;
+               goto local_entry_put;
 
-       ret = true;
+       if (_batadv_is_ap_isolated(tt_local_entry, tt_global_entry))
+               ret = true;
 
-out:
+       batadv_tt_global_entry_put(tt_global_entry);
+local_entry_put:
+       batadv_tt_local_entry_put(tt_local_entry);
+vlan_put:
        batadv_softif_vlan_put(vlan);
-       if (tt_global_entry)
-               batadv_tt_global_entry_put(tt_global_entry);
-       if (tt_local_entry)
-               batadv_tt_local_entry_put(tt_local_entry);
        return ret;
 }
 
-- 
2.7.2