Re: [PATCH net-next V10 1/6] devlink: Extend devlink rate API with traffic classes bandwidth management

A few quick comments here as the test is failing

On Tue, 20 May 2025 21:38:02 +0300 Tariq Toukan wrote:

•  -
  

•    name: rate-tc-bws
  

•    type: nest
  

•    multi-attr: true
  

•    nested-attributes: dl-rate-tc-bws
  

•  -
  

•    name: rate-tc-index
  

•    type: u8
  

•    checks:
  

•      min: 0
  

•      max: rate-tc-index-max
  

no need for min: 0 on an unsigned type ?

•  -
  

•    name: rate-tc-bw
  

•    type: u32
  

•    doc: |
  

•         Specifies the bandwidth allocation for the Traffic Class as a
  

•         percentage.
  

•    checks:
  

•      min: 0
  

•      max: 100
  

Why in percentage? I don't think any existing param in devlink rate or net shapers is in percentage right? Not according to what i can grok about the uAPI.

+static int devlink_nl_rate_tc_bw_parse(struct nlattr *parent_nest, u32 *tc_bw,

• 		       unsigned long *bitmap, struct netlink_ext_ack *extack)
  

+{

• struct nlattr *tb[DEVLINK_ATTR_MAX + 1];
• u8 tc_index;
• nla_parse_nested(tb, DEVLINK_ATTR_MAX, parent_nest, devlink_dl_rate_tc_bws_nl_policy,

Let's error check this, I get that we already validated via the policy but what if we do memory allocations during parsing one day, or some other failure-prone operation.. better check the return value.

nit: over 80 chars for no good reason, the line overflows anyway. Please use checkpatch --max-line-width=80 for core code, at the very least.

• 	 extack);
  

• if (!tb[DEVLINK_ATTR_RATE_TC_INDEX]) {

• NL_SET_ERR_ATTR_MISS(extack, parent_nest, DEVLINK_ATTR_RATE_TC_INDEX);
  

• return -EINVAL;
  

• }
• tc_index = nla_get_u8(tb[DEVLINK_ATTR_RATE_TC_INDEX]);
• if (!tb[DEVLINK_ATTR_RATE_TC_BW]) {

• NL_SET_ERR_ATTR_MISS(extack, parent_nest, DEVLINK_ATTR_RATE_TC_BW);
  

• return -EINVAL;
  

• }
• if (test_and_set_bit(tc_index, bitmap)) {

• NL_SET_ERR_MSG_FMT(extack, "Duplicate traffic class index specified (%u)",
  

• 		   tc_index);
  

• return -EINVAL;
  

• }
• tc_bw[tc_index] = nla_get_u32(tb[DEVLINK_ATTR_RATE_TC_BW]);
• return 0;

+}

+static int devlink_nl_rate_tc_bw_set(struct devlink_rate *devlink_rate,

• 		     struct genl_info *info)
  

+{

• DECLARE_BITMAP(bitmap, DEVLINK_RATE_TCS_MAX) = {};
• struct devlink *devlink = devlink_rate->devlink;
• const struct devlink_ops *ops = devlink->ops;
• int rem, err = -EOPNOTSUPP, i, total = 0;
• u32 tc_bw[DEVLINK_RATE_TCS_MAX] = {};
• struct nlattr *attr;
• nla_for_each_attr(attr, genlmsg_data(info->genlhdr),

• 	  genlmsg_len(info->genlhdr), rem) {
  

nla_for_each_attr_type() ? or better still add a _type() version of nlmsg_for_each_attr() ?

• if (nla_type(attr) == DEVLINK_ATTR_RATE_TC_BWS) {
  

• 	err = devlink_nl_rate_tc_bw_parse(attr, tc_bw, bitmap, info->extack);
  

• 	if (err)
  

• 		return err;
  

• }
  

• }