diff options
Diffstat (limited to 'net/sched/cls_u32.c')
| -rw-r--r-- | net/sched/cls_u32.c | 30 |
1 files changed, 28 insertions, 2 deletions
diff --git a/net/sched/cls_u32.c b/net/sched/cls_u32.c index 09487afbfd51..cab9e9b43967 100644 --- a/net/sched/cls_u32.c +++ b/net/sched/cls_u32.c @@ -78,8 +78,11 @@ struct tc_u_hnode { struct tc_u_common *tp_c; int refcnt; unsigned int divisor; - struct tc_u_knode __rcu *ht[1]; struct rcu_head rcu; + /* The 'ht' field MUST be the last field in structure to allow for + * more entries allocated at end of structure. + */ + struct tc_u_knode __rcu *ht[1]; }; struct tc_u_common { @@ -460,13 +463,35 @@ static int u32_destroy_hnode(struct tcf_proto *tp, struct tc_u_hnode *ht) return -ENOENT; } -static void u32_destroy(struct tcf_proto *tp) +static bool ht_empty(struct tc_u_hnode *ht) +{ + unsigned int h; + + for (h = 0; h <= ht->divisor; h++) + if (rcu_access_pointer(ht->ht[h])) + return false; + + return true; +} + +static bool u32_destroy(struct tcf_proto *tp, bool force) { struct tc_u_common *tp_c = tp->data; struct tc_u_hnode *root_ht = rtnl_dereference(tp->root); WARN_ON(root_ht == NULL); + if (!force) { + if (root_ht) { + if (root_ht->refcnt > 1) + return false; + if (root_ht->refcnt == 1) { + if (!ht_empty(root_ht)) + return false; + } + } + } + if (root_ht && --root_ht->refcnt == 0) u32_destroy_hnode(tp, root_ht); @@ -491,6 +516,7 @@ static void u32_destroy(struct tcf_proto *tp) } tp->data = NULL; + return true; } static int u32_delete(struct tcf_proto *tp, unsigned long arg) |