diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index dd8a65cef6e1..e98313cd710a 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -76,6 +76,7 @@ struct fl_flow_mask { struct list_head filters; struct rcu_work rwork; struct list_head list; + refcount_t refcnt; }; struct fl_flow_tmplt { @@ -320,6 +321,7 @@ static int fl_init(struct tcf_proto *tp) static void fl_mask_free(struct fl_flow_mask *mask) { + WARN_ON(!list_empty(&mask->filters)); rhashtable_destroy(&mask->ht); kfree(mask); } @@ -335,7 +337,7 @@ static void fl_mask_free_work(struct work_struct *work) static bool fl_mask_put(struct cls_fl_head *head, struct fl_flow_mask *mask, bool async) { - if (!list_empty(&mask->filters)) + if (!refcount_dec_and_test(&mask->refcnt)) return false; rhashtable_remove_fast(&head->ht, &mask->ht_node, mask_ht_params); @@ -1301,6 +1303,7 @@ static struct fl_flow_mask *fl_create_new_mask(struct cls_fl_head *head, INIT_LIST_HEAD_RCU(&newmask->filters); + refcount_set(&newmask->refcnt, 1); err = rhashtable_insert_fast(&head->ht, &newmask->ht_node, mask_ht_params); if (err) @@ -1324,9 +1327,13 @@ static int fl_check_assign_mask(struct cls_fl_head *head, struct fl_flow_mask *mask) { struct fl_flow_mask *newmask; + int ret = 0; + rcu_read_lock(); fnew->mask = rhashtable_lookup_fast(&head->ht, mask, mask_ht_params); if (!fnew->mask) { + rcu_read_unlock(); + if (fold) return -EINVAL; @@ -1335,11 +1342,15 @@ static int fl_check_assign_mask(struct cls_fl_head *head, return PTR_ERR(newmask); fnew->mask = newmask; + return 0; } else if (fold && fold->mask != fnew->mask) { - return -EINVAL; + ret = -EINVAL; + } else if (!refcount_inc_not_zero(&fnew->mask->refcnt)) { + /* Mask was deleted concurrently, try again */ + ret = -EAGAIN; } - - return 0; + rcu_read_unlock(); + return ret; } static int fl_set_parms(struct net *net, struct tcf_proto *tp, @@ -1476,6 +1487,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, list_replace_rcu(&fold->list, &fnew->list); fold->deleted = true; + fl_mask_put(head, fold->mask, true); if (!tc_skip_hw(fold->flags)) fl_hw_destroy_filter(tp, fold, NULL); tcf_unbind_filter(tp, &fold->res); @@ -1525,7 +1537,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, if (!tc_skip_hw(fnew->flags)) fl_hw_destroy_filter(tp, fnew, NULL); errout_mask: - fl_mask_put(head, fnew->mask, false); + fl_mask_put(head, fnew->mask, true); errout: tcf_exts_destroy(&fnew->exts); kfree(fnew);