[NET_SCHED] cls_u32: refcounting fix for u32_delete()

Deleting of nonroot hnodes mostly doesn't work in u32_delete():
refcnt == 1 is expected, but such hnodes' refcnts are initialized
with 0 and charged only with "link" nodes. Now they'll start with
1 like usual. Thanks to Patrick McHardy for an improving suggestion.

Signed-off-by: Jarek Poplawski <jarkao2@gmail.com>
Acked-by: Jamal Hadi Salim <hadi@cyberus.ca>
Signed-off-by: David S. Miller <davem@davemloft.net>

diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c
index c5c16b4b6e98d5e96eb7ee68ec4fd5e5f2d011e6..4d755444c449f04c6eb93a33ba9d20fc5f0a2a22 100644 (file)
--- a/net/sched/cls_u32.c
+++ b/net/sched/cls_u32.c
@@ -411,8 +411,10 @@ static void u32_destroy(struct tcf_proto *tp)
                        }
                }
 
-               for (ht=tp_c->hlist; ht; ht = ht->next)
+               for (ht = tp_c->hlist; ht; ht = ht->next) {
+                       ht->refcnt--;
                        u32_clear_hnode(tp, ht);
+               }
 
                while ((ht = tp_c->hlist) != NULL) {
                        tp_c->hlist = ht->next;
@@ -441,8 +443,12 @@ static int u32_delete(struct tcf_proto *tp, unsigned long arg)
        if (tp->root == ht)
                return -EINVAL;
 
-       if (--ht->refcnt == 0)
+       if (ht->refcnt == 1) {
+               ht->refcnt--;
                u32_destroy_hnode(tp, ht);
+       } else {
+               return -EBUSY;
+       }
 
        return 0;
 }
@@ -568,7 +574,7 @@ static int u32_change(struct tcf_proto *tp, unsigned long base, u32 handle,
                if (ht == NULL)
                        return -ENOBUFS;
                ht->tp_c = tp_c;
-               ht->refcnt = 0;
+               ht->refcnt = 1;
                ht->divisor = divisor;
                ht->handle = handle;
                ht->prio = tp->prio;