Re: [PATCH iproute2-next v6 2/2] rdma: display resource limits in curr/max format

[David Ahern <dsahern@kernel.org>]

On 7/13/26 7:12 AM, Tao Cui wrote:
> @@ -55,7 +55,26 @@ static int res_print_summary(struct nlattr **tb)
>  
>  		name = mnl_attr_get_str(nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_NAME]);
>  		curr = mnl_attr_get_u64(nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]);
> -		res_print_u64(name, curr, nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_CURR]);
> +		if (nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]) {
> +			uint64_t max;
> +			char max_name[64];
> +
> +			max = mnl_attr_get_u64(
> +				nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]);
> +			snprintf(max_name, sizeof(max_name), "%s-max", name);
> +			print_u64(PRINT_JSON, name, NULL, curr);
> +			print_u64(PRINT_JSON, max_name, NULL, max);
> +			if (!is_json_context()) {
> +				char buf[64];
> +
> +				snprintf(buf, sizeof(buf), "%s %" PRIu64 "/%" PRIu64 " ",
> +					 name, curr, max);
> +				pr_out("%s", buf);

claude review:

The feature and backward-compat approach look correct.  A couple of
nits below.

> +             if (nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]) {
> +                     uint64_t max;
> +                     char max_name[64];
> +
> +                     max = mnl_attr_get_u64(
> +
nla_line[RDMA_NLDEV_ATTR_RES_SUMMARY_ENTRY_MAX]);
> +                     snprintf(max_name, sizeof(max_name), "%s-max",
name);
> +                     print_u64(PRINT_JSON, name, NULL, curr);
> +                     print_u64(PRINT_JSON, max_name, NULL, max);
> +                     if (!is_json_context()) {
> +                             char buf[64];
> +
> +                             snprintf(buf, sizeof(buf), "%s %" PRIu64
"/%" PRIu64 " ",
> +                                      name, curr, max);
> +                             pr_out("%s", buf);
> +                     }

The intermediate buf[] is unnecessary; pr_out() accepts a format string
directly.  The snprintf -> pr_out("%s") dance also silently truncates if
`name` is unusually long, since two u64 values and a slash can consume
up to 42 bytes, leaving only 22 bytes in a 64-byte buffer for the name.
While current RDMA resource names are short, the kernel is the source of
`name`, so it is better not to rely on that.

  if (!is_json_context())
      pr_out("%s %" PRIu64 "/%" PRIu64 " ", name, curr, max);

Similarly, the max_name[] buffer for the JSON key has the same size
concern; a 64-byte buffer with snprintf("%s-max", name) silently
truncates for any name longer than 59 characters.  Again unlikely in
practice, but worth noting if this pattern is copied elsewhere.

No functional issue with the netlink policy addition in utils.c or the
backward-compatible fallback to res_print_u64().

###

in addition, please provide json output in the commit message.