Bug 1255316

Summary: tc does not allow to attach pfifo_fast qdisc
Product: Red Hat Enterprise Linux 7 Reporter: Phil Sutter <psutter>
Component: iprouteAssignee: Phil Sutter <psutter>
Status: CLOSED ERRATA QA Contact: Jaroslav Aster <jaster>
Severity: medium Docs Contact:
Priority: medium    
Version: 7.2   
Target Milestone: rc   
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
Whiteboard:
Fixed In Version: iproute-3.10.0-52.el7 Doc Type: Bug Fix
Doc Text:
Story Points: ---
Clone Of:
: 1261115 (view as bug list) Environment:
Last Closed: 2015-11-19 14:43:08 UTC Type: Bug
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:

Description Phil Sutter 2015-08-20 09:36:06 UTC
'tc' program of current RHEL7's iproute package does not allow to attach pfifo_fast qdisc to a device:

# tc qd show dev eth0
qdisc pfifo_fast 0: root refcnt 2 bands 3 priomap  1 2 2 2 1 2 0 0 1 1 1 1 1 1 1 1
# tc qd replace dev eth0 root pfifo
# tc qd show dev eth0
qdisc pfifo 8004: root refcnt 2 limit 1000p
# tc qd replace dev eth0 root pfifo_fast
qdisc 'pfifo_fast' does not support option parsing

This is an obvious bug (no options were given above, still tc complains). It has been fixed upstream:

commit e9e78b0db0e023035e346ba67de838be851eb665
Author: Stephen Hemminger <stephen>
Date:   Mon Aug 26 08:41:19 2013 -0700

    tc: allow qdisc without options
    
    Pfifo_fast needs no options. So don't force it to have parsing code.

commit 0a502b21e30be835dcad8d9c6023a41da8709eb1
Author: Stephen Hemminger <stephen>
Date:   Sun Oct 27 12:26:47 2013 -0700

    Fix handling of qdis without options
    
    Some qdisc like htb want the parse_qopt to be called even if no options
    present. Fixes regression caused by:
    
    e9e78b0db0e023035e346ba67de838be851eb665 is the first bad commit
    commit e9e78b0db0e023035e346ba67de838be851eb665
    Author: Stephen Hemminger <stephen>
    Date:   Mon Aug 26 08:41:19 2013 -0700
    
        tc: allow qdisc without options

Comment 4 errata-xmlrpc 2015-11-19 14:43:08 UTC
Since the problem described in this bug report should be
resolved in a recent advisory, it has been closed with a
resolution of ERRATA.

For information on the advisory, and where to find the updated
files, follow the link below.

If the solution does not work for you, open a new bug report.

https://rhn.redhat.com/errata/RHBA-2015-2117.html