diff options
| -rw-r--r-- | net/sched/cls_flower.c | 24 |
1 files changed, 17 insertions, 7 deletions
diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c index c04247b403ed..dcf3aee5697e 100644 --- a/net/sched/cls_flower.c +++ b/net/sched/cls_flower.c @@ -437,10 +437,20 @@ static void fl_hw_update_stats(struct tcf_proto *tp, struct cls_fl_filter *f) cls_flower.stats.lastused); } +static struct cls_fl_head *fl_head_dereference(struct tcf_proto *tp) +{ + /* Flower classifier only changes root pointer during init and destroy. + * Users must obtain reference to tcf_proto instance before calling its + * API, so tp->root pointer is protected from concurrent call to + * fl_destroy() by reference counting. + */ + return rcu_dereference_raw(tp->root); +} + static bool __fl_delete(struct tcf_proto *tp, struct cls_fl_filter *f, struct netlink_ext_ack *extack) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); bool async = tcf_exts_get_net(&f->exts); bool last; @@ -472,7 +482,7 @@ static void fl_destroy_sleepable(struct work_struct *work) static void fl_destroy(struct tcf_proto *tp, bool rtnl_held, struct netlink_ext_ack *extack) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); struct fl_flow_mask *mask, *next_mask; struct cls_fl_filter *f, *next; @@ -490,7 +500,7 @@ static void fl_destroy(struct tcf_proto *tp, bool rtnl_held, static void *fl_get(struct tcf_proto *tp, u32 handle) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); return idr_find(&head->handle_idr, handle); } @@ -1308,7 +1318,7 @@ static int fl_change(struct net *net, struct sk_buff *in_skb, void **arg, bool ovr, bool rtnl_held, struct netlink_ext_ack *extack) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); struct cls_fl_filter *fold = *arg; struct cls_fl_filter *fnew; struct fl_flow_mask *mask; @@ -1446,7 +1456,7 @@ errout_mask_alloc: static int fl_delete(struct tcf_proto *tp, void *arg, bool *last, bool rtnl_held, struct netlink_ext_ack *extack) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); struct cls_fl_filter *f = arg; rhashtable_remove_fast(&f->mask->ht, &f->ht_node, @@ -1459,7 +1469,7 @@ static int fl_delete(struct tcf_proto *tp, void *arg, bool *last, static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg, bool rtnl_held) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); struct cls_fl_filter *f; arg->count = arg->skip; @@ -1478,7 +1488,7 @@ static void fl_walk(struct tcf_proto *tp, struct tcf_walker *arg, static int fl_reoffload(struct tcf_proto *tp, bool add, tc_setup_cb_t *cb, void *cb_priv, struct netlink_ext_ack *extack) { - struct cls_fl_head *head = rtnl_dereference(tp->root); + struct cls_fl_head *head = fl_head_dereference(tp); struct tc_cls_flower_offload cls_flower = {}; struct tcf_block *block = tp->chain->block; struct fl_flow_mask *mask; |