net: sched: extend proto ops to support unlocked classifiers

Add 'rtnl_held' flag to tcf proto change, delete, destroy, dump, walk
functions to track rtnl lock status. Extend users of these function in cls
API to propagate rtnl lock status to them. This allows classifiers to
obtain rtnl lock when necessary and to pass rtnl lock status to extensions
and driver offload callbacks.

Add flags field to tcf proto ops. Add flag value to indicate that
classifier doesn't require rtnl lock.

Signed-off-by: Vlad Buslov <vladbu@mellanox.com>
Acked-by: Jiri Pirko <jiri@mellanox.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 7 insertions, 5 deletions

diff --git a/net/sched/cls_route.c b/net/sched/cls_route.c
index 44b26038c4c4..e590c3a2999d 100644
--- a/net/sched/cls_route.c
+++ b/net/sched/cls_route.c
@@ -276,7 +276,8 @@ static void route4_queue_work(struct route4_filter *f)
         tcf_queue_work(&f->rwork, route4_delete_filter_work);
 }
 
-static void route4_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
+static void route4_destroy(struct tcf_proto *tp, bool rtnl_held,
+                           struct netlink_ext_ack *extack)
 {
         struct route4_head *head = rtnl_dereference(tp->root);
         int h1, h2;
@@ -312,7 +313,7 @@ static void route4_destroy(struct tcf_proto *tp, struct netlink_ext_ack *extack)
 }
 
 static int route4_delete(struct tcf_proto *tp, void *arg, bool *last,
-                         struct netlink_ext_ack *extack)
+                         bool rtnl_held, struct netlink_ext_ack *extack)
 {
         struct route4_head *head = rtnl_dereference(tp->root);
         struct route4_filter *f = arg;
@@ -468,7 +469,7 @@ static int route4_set_parms(struct net *net, struct tcf_proto *tp,
 static int route4_change(struct net *net, struct sk_buff *in_skb,
                          struct tcf_proto *tp, unsigned long base, u32 handle,
                          struct nlattr **tca, void **arg, bool ovr,
-                         struct netlink_ext_ack *extack)
+                         bool rtnl_held, struct netlink_ext_ack *extack)
 {
         struct route4_head *head = rtnl_dereference(tp->root);
         struct route4_filter __rcu **fp;
@@ -560,7 +561,8 @@ errout:
         return err;
 }
 
-static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
+static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg,
+                        bool rtnl_held)
 {
         struct route4_head *head = rtnl_dereference(tp->root);
         unsigned int h, h1;
@@ -597,7 +599,7 @@ static void route4_walk(struct tcf_proto *tp, struct tcf_walker *arg)
 }
 
 static int route4_dump(struct net *net, struct tcf_proto *tp, void *fh,
-                       struct sk_buff *skb, struct tcmsg *t)
+                       struct sk_buff *skb, struct tcmsg *t, bool rtnl_held)
 {
         struct route4_filter *f = fh;
         struct nlattr *nest;