Re: [PATCH net] net/sched: cls_api: Fix nooffloaddevcnt counter in indr block call success

[Jiri Pirko <jiri@resnulli.us>]

Please use get_maintainers script to get list of ccs.

Mon, Sep 16, 2019 at 12:15:34PM CEST, wenxu@ucloud.cn wrote:
>From: wenxu <wenxu@ucloud.cn>
>
>When a block bind with a dev which support indr block call(vxlan/gretap
>device). It can bind success but with nooffloaddevcnt++. It will fail
>when replace the hw filter in tc_setup_cb_call with skip_sw mode for
>checkout the nooffloaddevcnt and skip_sw.

I read this paragraph 5 times, I still don't understand :( Could you
please re-phrase?


>
>if (block->nooffloaddevcnt && err_stop)
>	return -EOPNOTSUPP;
>
>So with this patch, if the indr block call success, it will not modify
>the nooffloaddevcnt counter.
>
>Fixes: 7f76fa36754b ("net: sched: register callbacks for indirect tc block binds")
>Signed-off-by: wenxu <wenxu@ucloud.cn>
>---
> net/sched/cls_api.c | 27 +++++++++++++++------------
> 1 file changed, 15 insertions(+), 12 deletions(-)
>
>diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>index efd3cfb..8a1e3a5 100644
>--- a/net/sched/cls_api.c
>+++ b/net/sched/cls_api.c
>@@ -766,10 +766,10 @@ void tc_indr_block_cb_unregister(struct net_device *dev,
> }
> EXPORT_SYMBOL_GPL(tc_indr_block_cb_unregister);
> 
>-static void tc_indr_block_call(struct tcf_block *block, struct net_device *dev,
>-			       struct tcf_block_ext_info *ei,
>-			       enum flow_block_command command,
>-			       struct netlink_ext_ack *extack)
>+static int tc_indr_block_call(struct tcf_block *block, struct net_device *dev,
>+			      struct tcf_block_ext_info *ei,
>+			      enum flow_block_command command,
>+			      struct netlink_ext_ack *extack)
> {
> 	struct tc_indr_block_cb *indr_block_cb;
> 	struct tc_indr_block_dev *indr_dev;
>@@ -785,7 +785,7 @@ static void tc_indr_block_call(struct tcf_block *block, struct net_device *dev,
> 
> 	indr_dev = tc_indr_block_dev_lookup(dev);
> 	if (!indr_dev)
>-		return;
>+		return -ENOENT;
> 
> 	indr_dev->block = command == FLOW_BLOCK_BIND ? block : NULL;
> 
>@@ -793,7 +793,10 @@ static void tc_indr_block_call(struct tcf_block *block, struct net_device *dev,
> 		indr_block_cb->cb(dev, indr_block_cb->cb_priv, TC_SETUP_BLOCK,
> 				  &bo);
> 
>-	tcf_block_setup(block, &bo);
>+	if (list_empty(&bo.cb_list))
>+		return -EOPNOTSUPP;

How is this part related to the rest of the patch?

>+
>+	return tcf_block_setup(block, &bo);
> }
> 
> static bool tcf_block_offload_in_use(struct tcf_block *block)
>@@ -849,14 +852,14 @@ static int tcf_block_offload_bind(struct tcf_block *block, struct Qdisc *q,
> 	if (err)
> 		return err;
> 
>-	tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
> 	return 0;
> 
> no_offload_dev_inc:
> 	if (tcf_block_offload_in_use(block))
> 		return -EOPNOTSUPP;
>-	block->nooffloaddevcnt++;
>-	tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
>+	err = tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
>+	if (err)
>+		block->nooffloaddevcnt++;
> 	return 0;
> }
> 
>@@ -866,8 +869,6 @@ static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
> 	struct net_device *dev = q->dev_queue->dev;
> 	int err;
> 
>-	tc_indr_block_call(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
>-
> 	if (!dev->netdev_ops->ndo_setup_tc)
> 		goto no_offload_dev_dec;
> 	err = tcf_block_offload_cmd(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
>@@ -876,7 +877,9 @@ static void tcf_block_offload_unbind(struct tcf_block *block, struct Qdisc *q,
> 	return;
> 
> no_offload_dev_dec:
>-	WARN_ON(block->nooffloaddevcnt-- == 0);
>+	err = tc_indr_block_call(block, dev, ei, FLOW_BLOCK_UNBIND, NULL);
>+	if (err)
>+		WARN_ON(block->nooffloaddevcnt-- == 0);
> }
> 
> static int
>-- 
>1.8.3.1
>