[PATCH net-next v2 07/12] net: sched: flower: protect masks list with spinlock

[Vlad Buslov]

Protect modifications of flower masks list with spinlock to remove
dependency on rtnl lock and allow concurrent access.

Signed-off-by: Vlad Buslov <vla...@mellanox.com>
Acked-by: Jiri Pirko <j...@mellanox.com>
---
 net/sched/cls_flower.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/net/sched/cls_flower.c b/net/sched/cls_flower.c
index 92478bb122d3..db47828ea5e2 100644
--- a/net/sched/cls_flower.c
+++ b/net/sched/cls_flower.c
@@ -88,6 +88,7 @@ struct fl_flow_tmplt {
 
 struct cls_fl_head {
        struct rhashtable ht;
+       spinlock_t masks_lock; /* Protect masks list */
        struct list_head masks;
        struct rcu_work rwork;
        struct idr handle_idr;
@@ -312,6 +313,7 @@ static int fl_init(struct tcf_proto *tp)
        if (!head)
                return -ENOBUFS;
 
+       spin_lock_init(&head->masks_lock);
        INIT_LIST_HEAD_RCU(&head->masks);
        rcu_assign_pointer(tp->root, head);
        idr_init(&head->handle_idr);
@@ -341,7 +343,11 @@ static bool fl_mask_put(struct cls_fl_head *head, struct 
fl_flow_mask *mask,
                return false;
 
        rhashtable_remove_fast(&head->ht, &mask->ht_node, mask_ht_params);
+
+       spin_lock(&head->masks_lock);
        list_del_rcu(&mask->list);
+       spin_unlock(&head->masks_lock);
+
        if (async)
                tcf_queue_work(&mask->rwork, fl_mask_free_work);
        else
@@ -1312,7 +1318,9 @@ static struct fl_flow_mask *fl_create_new_mask(struct 
cls_fl_head *head,
        /* Wait until any potential concurrent users of mask are finished */
        synchronize_rcu();
 
+       spin_lock(&head->masks_lock);
        list_add_tail_rcu(&newmask->list, &head->masks);
+       spin_unlock(&head->masks_lock);
 
        return newmask;
 
-- 
2.13.6