Skip site navigation (1)Skip section navigation (2)
Date:      Sun, 8 Aug 2010 07:04:27 +0000 (UTC)
From:      Xin LI <delphij@FreeBSD.org>
To:        cvs-src-old@freebsd.org
Subject:   cvs commit: src/sys/netinet ip_carp.c
Message-ID:  <201008080704.o7874h1T043956@repoman.freebsd.org>

next in thread | raw e-mail | index | archive | help
delphij     2010-08-08 07:04:27 UTC

  FreeBSD src repository

  Modified files:
    sys/netinet          ip_carp.c 
  Log:
  SVN rev 211059 on 2010-08-08 07:04:27Z by delphij
  
  Address an edge condition that we found at work, where the carp(4)
  interface goes to issue LINK_UP, then LINK_DOWN, then LINK_UP at
  cold boot.  This behavior is not observed when carp(4) interface
  is created slightly later, when the underlying interface is fully
  up.
  
  Before this change what happen at boot is roughly:
  
   - ifconfig creates em0 interface;
   - ifconfig clones a carp device using em0;
     (em0's link state is DOWN at this point)
   - carp state: INIT -> BACKUP [*]
   - carp state: BACKUP -> MASTER
   - [Some negotiate between em0 and switch]
   - em0 kicks up link state change event
     (em0's link state is now up DOWN at this point)
   - do_link_state_change() -> carp_carpdev_state()
   - carp state: MASTER -> INIT (via carp_set_state(sc, INIT)) [+]
   - carp state: INIT -> BACKUP
   - carp state: BACKUP -> MASTER
  
  At the [*] stage, em0 did not received any broadcast message from other
  node, and assume our node is the master, thus carp(4) sets the link
  state to "UP" after becoming a master.  At [+], the master status
  is forcely set to "INIT", then an election is casted, after which our
  node would actually become a master.
  
  We believe that at the [*] stage, the master status should remain as
  "INIT" since the underlying parent interface's link state is not up.
  
  Obtained from:  iXsystems, Inc.
  Reported by:    jpaetzel
  MFC after:      2 months
  
  Revision  Changes    Path
  1.77      +2 -1      src/sys/netinet/ip_carp.c



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?201008080704.o7874h1T043956>