Re: [patch net-next] net: sched: move block device tracking into tcf_block_get/put_ext()

Jiri Pirko
2024-01-10T14:08:45Z

Wed, Jan 10, 2024 at 01:09:55PM CET, idosch@idosch.org wrote:
>On Thu, Jan 04, 2024 at 01:58:44PM +0100, Jiri Pirko wrote:
>> diff --git a/net/sched/cls_api.c b/net/sched/cls_api.c
>> index adf5de1ff773..253b26f2eddd 100644
>> --- a/net/sched/cls_api.c
>> +++ b/net/sched/cls_api.c
>> @@ -1428,6 +1428,7 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
>> struct tcf_block_ext_info *ei,
>> struct netlink_ext_ack *extack)
>> {
>> + struct net_device *dev = qdisc_dev(q);
>> struct net *net = qdisc_net(q);
>> struct tcf_block *block = NULL;
>> int err;
>> @@ -1461,9 +1462,18 @@ int tcf_block_get_ext(struct tcf_block **p_block, struct Qdisc *q,
>> if (err)
>> goto err_block_offload_bind;
>>
>> + if (tcf_block_shared(block)) {
>> + err = xa_insert(&block->ports, dev->ifindex, dev, GFP_KERNEL);
>> + if (err) {
>> + NL_SET_ERR_MSG(extack, "block dev insert failed");
>> + goto err_dev_insert;
>> + }
>> + }
>
>While this patch fixes the original issue, it creates another one:
>
># ip link add name swp1 type dummy
># tc qdisc replace dev swp1 root handle 10: prio bands 8 priomap 7 6 5 4 3 2 1
># tc qdisc add dev swp1 parent 10:8 handle 108: red limit 1000000 min 200000 max 200001 probability 1.0 avpkt 8000 burst 38 qevent early_drop block 10
>RED: set bandwidth to 10Mbit
># tc qdisc add dev swp1 parent 10:7 handle 107: red limit 1000000 min 500000 max 500001 probability 1.0 avpkt 8000 burst 63 qevent early_drop block 10
>RED: set bandwidth to 10Mbit
>Error: block dev insert failed.
>
>The reproducer does not fail if I revert this patch and apply Victor's
>[1] instead.
>
>[1] https://lore.kernel.org/netdev/20231231172320.245375-1-victor@mojatatu.com/

Will fix. Thanks!

>
>> +
>> *p_block = block;
>> return 0;
>>
>> +err_dev_insert:
>> err_block_offload_bind:
>> tcf_chain0_head_change_cb_del(block, ei);
>> err_chain0_head_change_cb_add: