path: root/net/sched/cls_fw.c
diff options
authorCong Wang <cwang@twopensource.com>2015-03-06 11:47:59 -0800
committerDavid S. Miller <davem@davemloft.net>2015-03-09 15:35:55 -0400
commit1e052be69d045c8d0f82ff1116fd3e5a79661745 (patch)
treec237348cf8f28ca178c3ebfcec0e0013ef18b4c5 /net/sched/cls_fw.c
parentnet/macb: Update DT bindings documentation (diff)
net_sched: destroy proto tp when all filters are gone
Kernel automatically creates a tp for each (kind, protocol, priority) tuple, which has handle 0, when we add a new filter, but it still is left there after we remove our own, unless we don't specify the handle (literally means all the filters under the tuple). For example this one is left: # tc filter show dev eth0 filter parent 8001: protocol arp pref 49152 basic The user-space is hard to clean up these for kernel because filters like u32 are organized in a complex way. So kernel is responsible to remove it after all filters are gone. Each type of filter has its own way to store the filters, so each type has to provide its way to check if all filters are gone. Cc: Jamal Hadi Salim <jhs@mojatatu.com> Signed-off-by: Cong Wang <cwang@twopensource.com> Signed-off-by: Cong Wang <xiyou.wangcong@gmail.com> Acked-by: Jamal Hadi Salim<jhs@mojatatu.com> Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to '')
1 files changed, 9 insertions, 2 deletions
diff --git a/net/sched/cls_fw.c b/net/sched/cls_fw.c
index 9d9aa3e82b10..715e01e5910a 100644
--- a/net/sched/cls_fw.c
+++ b/net/sched/cls_fw.c
@@ -133,14 +133,20 @@ static void fw_delete_filter(struct rcu_head *head)
-static void fw_destroy(struct tcf_proto *tp)
+static bool fw_destroy(struct tcf_proto *tp, bool force)
struct fw_head *head = rtnl_dereference(tp->root);
struct fw_filter *f;
int h;
if (head == NULL)
- return;
+ return true;
+ if (!force) {
+ for (h = 0; h < HTSIZE; h++)
+ if (rcu_access_pointer(head->ht[h]))
+ return false;
+ }
for (h = 0; h < HTSIZE; h++) {
while ((f = rtnl_dereference(head->ht[h])) != NULL) {
@@ -152,6 +158,7 @@ static void fw_destroy(struct tcf_proto *tp)
kfree_rcu(head, rcu);
+ return true;
static int fw_delete(struct tcf_proto *tp, unsigned long arg)