1. 07 Sep, 2004 8 commits
  2. 03 Sep, 2004 1 commit
    • Herbert Xu's avatar
      [NET]: Add reference counting to neigh_parms. · 10bc9563
      Herbert Xu authored
      I've added a refcnt on neigh_parms as well as a dead flag.  The latter
      is checked under the tbl_lock before adding a neigh entry to the hash
      table.
      
      The non-trivial bit of the patch is the first chunk of net/core/neighbour.c.
      I removed that line because not doing so would mean that I have to drop
      the reference to the parms right there.  That would've lead to race
      conditions since many places dereference neigh->parms without holding
      locks.  It's also unnecessary to reset n->parms since we're no longer
      in a hurry to see it go due to the new ref counting.
      
      You'll also notice that I've put all dereferences of dev->*_ptr under
      the rcu_read_lock().  Without this we may get a neigh_parms that's
      already been released.
      
      Incidentally a lot of these places were racy even before the RCU change.
      For example, in the IPv6 case neigh->parms may be set to a value that's
      just been released.
      
      Finally in order to make sure that all stale entries are purged as
      quickly as possible I've added neigh_ifdown/arp_ifdown calls after
      every neigh_parms_release call.  In many cases we now have multiple
      calls to neigh_ifdown in the shutdown path.  I didn't remove the
      earlier calls because there may be hidden dependencies for them to
      be there.  Once the respective maintainers have looked at them we
      can probably remove most of them.
      Signed-off-by: default avatarHerbert Xu <herbert@gondor.apana.org.au>
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      10bc9563
  3. 02 Sep, 2004 31 commits