[PATCH net v3] net/sched: cls_api: Fix nooffloaddevcnt counter when indr block call success

[wenxu]

From: wenxu <we...@ucloud.cn>

A vxlan or gretap device offload through indr block methord. If the device
successfully bind with a real hw through indr block call, It also add
nooffloadcnt counter. This counter will lead the rule add failed in
fl_hw_replace_filter-->tc_setup_cb_call with skip_sw flags.

In the tc_setup_cb_call will check the nooffloaddevcnt and skip_sw flags
as following:
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 <we...@ucloud.cn>
---
v3: rebase to the net

 net/sched/cls_api.c | 30 +++++++++++++++++-------------
 1 file changed, 17 insertions(+), 13 deletions(-)

diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
index 32577c2..c980127 100644
--- a/net/sched/cls_api.c
+++ b/net/sched/cls_api.c
@@ -607,11 +607,11 @@ static void tc_indr_block_get_and_ing_cmd(struct 
net_device *dev,
        tc_indr_block_ing_cmd(dev, block, cb, cb_priv, command);
 }
 
-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 flow_block_offload bo = {
                .command        = command,
@@ -621,10 +621,15 @@ static void tc_indr_block_call(struct tcf_block *block,
                .block_shared   = tcf_block_shared(block),
                .extack         = extack,
        };
+
        INIT_LIST_HEAD(&bo.cb_list);
 
        flow_indr_block_call(dev, &bo, command);
-       tcf_block_setup(block, &bo);
+
+       if (list_empty(&bo.cb_list))
+               return -EOPNOTSUPP;
+
+       return tcf_block_setup(block, &bo);
 }
 
 static bool tcf_block_offload_in_use(struct tcf_block *block)
@@ -681,8 +686,6 @@ static int tcf_block_offload_bind(struct tcf_block *block, 
struct Qdisc *q,
                goto no_offload_dev_inc;
        if (err)
                goto err_unlock;
-
-       tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
        up_write(&block->cb_lock);
        return 0;
 
@@ -691,9 +694,10 @@ static int tcf_block_offload_bind(struct tcf_block *block, 
struct Qdisc *q,
                err = -EOPNOTSUPP;
                goto err_unlock;
        }
+       err = tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
+       if (err)
+               block->nooffloaddevcnt++;
        err = 0;
-       block->nooffloaddevcnt++;
-       tc_indr_block_call(block, dev, ei, FLOW_BLOCK_BIND, extack);
 err_unlock:
        up_write(&block->cb_lock);
        return err;
@@ -706,8 +710,6 @@ static void tcf_block_offload_unbind(struct tcf_block 
*block, struct Qdisc *q,
        int err;
 
        down_write(&block->cb_lock);
-       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);
@@ -717,7 +719,9 @@ 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);
        up_write(&block->cb_lock);
 }
 
-- 
1.8.3.1