From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jarod Wilson Subject: Re: bond procfs hw addr prints Date: Mon, 13 Mar 2017 22:06:06 -0400 Message-ID: <8aa4aff4-e1b3-83b5-f453-c6485f540705@redhat.com> References: <597da6f1-c0fc-ae23-94d1-d0fb3abb3176@redhat.com> <10202.1489451284@famine> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev To: Jay Vosburgh Return-path: Received: from mx1.redhat.com ([209.132.183.28]:33840 "EHLO mx1.redhat.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752044AbdCNCGG (ORCPT ); Mon, 13 Mar 2017 22:06:06 -0400 In-Reply-To: <10202.1489451284@famine> Sender: netdev-owner@vger.kernel.org List-ID: On 2017-03-13 8:28 PM, Jay Vosburgh wrote: > Jarod Wilson wrote: > >> I've got a bug report for someone using a Intel OPA devices in a bond, and >> it appears these devices have a hardware address length of 20, opposed to >> the typical 6 on ethernet. When they dump /proc/net/bonding/bondX, it only >> prints the first 6 of the address, per %pM and mac_address_string(), while >> sysfs for the interface does print the right thing, since it uses >> sysfs_print_mac(), which takes a length argument. > > This (20 octet MAC length) is true for any Infiniband device. > >> So the question is... What's the best route to take here? Expand %pM to >> support variable length hardware addresses? Use sysfs_* in procfs? >> Reinvent the wheel? Nothing I've tinkered with just yet feels very clean, >> on top of not actually working yet. :) > > sysfs_format_mac (not _print_mac) uses "%*phC", len, addr in its > format string. Perhaps that format would be a better choice than %pM > for this case? Ah, I'd failed to fully grasp how %phC worked, had actually tried it w/o the * in there, and only the first char of the addr was printing. Working on an updated version that uses %*phC properly, which does look like the way to go here. (Didn't help that I was also looking at an older codebase that didn't have the sysfs_format_mac de-duplication). I'll try to have a tested patch in flight tomorrow. -- Jarod Wilson jarod@redhat.com