diff options
Diffstat (limited to 'net/sched/cls_api.c')
| -rw-r--r-- | net/sched/cls_api.c | 68 |
1 files changed, 51 insertions, 17 deletions
diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c index 0b2219adf520..045d13679ad6 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) @@ -266,23 +275,30 @@ err_chain_create: } EXPORT_SYMBOL(tcf_block_get); -void tcf_block_put(struct tcf_block *block) +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; - 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. - */ + /* At this point, all the chains should have refcnt == 1. */ + rtnl_lock(); + list_for_each_entry_safe(chain, tmp, &block->chain_list, list) + tcf_chain_put(chain); + rtnl_unlock(); + kfree(block); +} - /* Wait for existing RCU callbacks to cool down. */ - rcu_barrier(); +/* 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. + */ +static void tcf_block_put_deferred(struct work_struct *work) +{ + struct tcf_block *block = container_of(work, struct tcf_block, work); + struct tcf_chain *chain; + rtnl_lock(); /* 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) @@ -292,13 +308,27 @@ void tcf_block_put(struct tcf_block *block) list_for_each_entry(chain, &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(); + tcf_queue_work(&block->work); + rtnl_unlock(); +} - /* 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); +void tcf_block_put(struct tcf_block *block) +{ + if (!block) + return; + + INIT_WORK(&block->work, tcf_block_put_deferred); + /* Wait for existing RCU callbacks to cool down, make sure their works + * have been queued before this. We can not flush pending works here + * because we are holding the RTNL lock. + */ + rcu_barrier(); + tcf_queue_work(&block->work); } EXPORT_SYMBOL(tcf_block_put); @@ -1030,6 +1060,10 @@ 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, |