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-rw-r--r--net/sched/cls_api.c60
1 files changed, 37 insertions, 23 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 0b2219a..b2d3107 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -77,6 +77,8 @@ out:
}
EXPORT_SYMBOL(register_tcf_proto_ops);
+static struct workqueue_struct *tc_filter_wq;
+
int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
{
struct tcf_proto_ops *t;
@@ -86,6 +88,7 @@ int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
* tcf_proto_ops's destroy() handler.
*/
rcu_barrier();
+ flush_workqueue(tc_filter_wq);
write_lock(&cls_mod_lock);
list_for_each_entry(t, &tcf_proto_base, head) {
@@ -100,6 +103,12 @@ int unregister_tcf_proto_ops(struct tcf_proto_ops *ops)
}
EXPORT_SYMBOL(unregister_tcf_proto_ops);
+bool tcf_queue_work(struct work_struct *work)
+{
+ return queue_work(tc_filter_wq, work);
+}
+EXPORT_SYMBOL(tcf_queue_work);
+
/* Select new prio value from the range, managed by kernel. */
static inline u32 tcf_auto_prio(struct tcf_proto *tp)
@@ -266,6 +275,23 @@ err_chain_create:
}
EXPORT_SYMBOL(tcf_block_get);
+static void tcf_block_put_final(struct work_struct *work)
+{
+ struct tcf_block *block = container_of(work, struct tcf_block, work);
+ struct tcf_chain *chain, *tmp;
+
+ rtnl_lock();
+ /* Only chain 0 should be still here. */
+ list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
+ tcf_chain_put(chain);
+ rtnl_unlock();
+ kfree(block);
+}
+
+/* XXX: Standalone actions are not allowed to jump to any chain, and bound
+ * actions should be all removed after flushing. However, filters are now
+ * destroyed in tc filter workqueue with RTNL lock, they can not race here.
+ */
void tcf_block_put(struct tcf_block *block)
{
struct tcf_chain *chain, *tmp;
@@ -273,32 +299,15 @@ void tcf_block_put(struct tcf_block *block)
if (!block)
return;
- /* XXX: Standalone actions are not allowed to jump to any chain, and
- * bound actions should be all removed after flushing. However,
- * filters are destroyed in RCU callbacks, we have to hold the chains
- * first, otherwise we would always race with RCU callbacks on this list
- * without proper locking.
- */
-
- /* Wait for existing RCU callbacks to cool down. */
- rcu_barrier();
-
- /* Hold a refcnt for all chains, except 0, in case they are gone. */
- list_for_each_entry(chain, &block->chain_list, list)
- if (chain->index)
- tcf_chain_hold(chain);
-
- /* No race on the list, because no chain could be destroyed. */
- list_for_each_entry(chain, &block->chain_list, list)
+ list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
tcf_chain_flush(chain);
- /* Wait for RCU callbacks to release the reference count. */
+ INIT_WORK(&block->work, tcf_block_put_final);
+ /* Wait for RCU callbacks to release the reference count and make
+ * sure their works have been queued before this.
+ */
rcu_barrier();
-
- /* At this point, all the chains should have refcnt == 1. */
- list_for_each_entry_safe(chain, tmp, &block->chain_list, list)
- tcf_chain_put(chain);
- kfree(block);
+ tcf_queue_work(&block->work);
}
EXPORT_SYMBOL(tcf_block_put);
@@ -879,6 +888,7 @@ void tcf_exts_destroy(struct tcf_exts *exts)
#ifdef CONFIG_NET_CLS_ACT
LIST_HEAD(actions);
+ ASSERT_RTNL();
tcf_exts_to_list(exts, &actions);
tcf_action_destroy(&actions, TCA_ACT_UNBIND);
kfree(exts->actions);
@@ -1030,6 +1040,10 @@ EXPORT_SYMBOL(tcf_exts_get_dev);
static int __init tc_filter_init(void)
{
+ tc_filter_wq = alloc_ordered_workqueue("tc_filter_workqueue", 0);
+ if (!tc_filter_wq)
+ return -ENOMEM;
+
rtnl_register(PF_UNSPEC, RTM_NEWTFILTER, tc_ctl_tfilter, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_DELTFILTER, tc_ctl_tfilter, NULL, 0);
rtnl_register(PF_UNSPEC, RTM_GETTFILTER, tc_ctl_tfilter,
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