@@ -236,8 +236,11 @@ static void tcf_chain0_head_change(struct tcf_chain *chain,
if (chain->index)
return;
+
+ mutex_lock(&block->lock);
list_for_each_entry(item, &block->chain0.filter_chain_list, list)
tcf_chain_head_change_item(item, tp_head);
+ mutex_unlock(&block->lock);
}
/* Returns true if block can be safely freed. */
@@ -748,8 +751,8 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
struct tcf_block_ext_info *ei,
struct netlink_ext_ack *extack)
{
- struct tcf_chain *chain0 = block->chain0.chain;
struct tcf_filter_chain_list_item *item;
+ struct tcf_chain *chain0;
item = kmalloc(sizeof(*item), GFP_KERNEL);
if (!item) {
@@ -758,9 +761,14 @@ tcf_chain0_head_change_cb_add(struct tcf_block *block,
}
item->chain_head_change = ei->chain_head_change;
item->chain_head_change_priv = ei->chain_head_change_priv;
+
+ mutex_lock(&block->lock);
+ chain0 = block->chain0.chain;
if (chain0 && chain0->filter_chain)
tcf_chain_head_change_item(item, chain0->filter_chain);
list_add(&item->list, &block->chain0.filter_chain_list);
+ mutex_unlock(&block->lock);
+
return 0;
}
@@ -768,20 +776,23 @@ static void
tcf_chain0_head_change_cb_del(struct tcf_block *block,
struct tcf_block_ext_info *ei)
{
- struct tcf_chain *chain0 = block->chain0.chain;
struct tcf_filter_chain_list_item *item;
+ mutex_lock(&block->lock);
list_for_each_entry(item, &block->chain0.filter_chain_list, list) {
if ((!ei->chain_head_change && !ei->chain_head_change_priv) ||
(item->chain_head_change == ei->chain_head_change &&
item->chain_head_change_priv == ei->chain_head_change_priv)) {
- if (chain0)
+ if (block->chain0.chain)
tcf_chain_head_change_item(item, NULL);
list_del(&item->list);
+ mutex_unlock(&block->lock);
+
kfree(item);
return;
}
}
+ mutex_unlock(&block->lock);
WARN_ON(1);
}
In order to remove dependency on rtnl lock, use block->lock to protect chain0 struct from concurrent modification. Rearrange code in chain0 callback add and del functions to only access chain0 when block->lock is held. Signed-off-by: Vlad Buslov <vladbu@mellanox.com> --- net/sched/cls_api.c | 17 ++++++++++++++--- 1 file changed, 14 insertions(+), 3 deletions(-)