1. 04 Mar, 2008 3 commits
  2. 07 Feb, 2008 1 commit
  3. 28 Jan, 2008 5 commits
  4. 10 Oct, 2007 1 commit
  5. 25 Apr, 2007 1 commit
  6. 25 Mar, 2007 1 commit
    • David S. Miller's avatar
      [IPV6]: Fix routing round-robin locking. · f11e6659
      David S. Miller authored
      
      
      As per RFC2461, section 6.3.6, item #2, when no routers on the
      matching list are known to be reachable or probably reachable we
      do round robin on those available routes so that we make sure
      to probe as many of them as possible to detect when one becomes
      reachable faster.
      
      Each routing table has a rwlock protecting the tree and the linked
      list of routes at each leaf.  The round robin code executes during
      lookup and thus with the rwlock taken as a reader.  A small local
      spinlock tries to provide protection but this does not work at all
      for two reasons:
      
      1) The round-robin list manipulation, as coded, goes like this (with
         read lock held):
      
      	walk routes finding head and tail
      
      	spin_lock();
      	rotate list using head and tail
      	spin_unlock();
      
         While one thread is rotating the list, another thread can
         end up with stale values of head and tail and then proceed
         to corrupt the list when it gets the lock.  This ends up causing
         the OOPS in fib6_add() later onthat many people have been hitting.
      
      2) All the other code paths that run with the rwlock held as
         a reader do not expect the list to change on them, they
         expect it to remain completely fixed while they hold the
         lock in that way.
      
      So, simply stated, it is impossible to implement this correctly using
      a manipulation of the list without violating the rwlock locking
      semantics.
      
      Reimplement using a per-fib6_node round-robin pointer.  This way we
      don't need to manipulate the list at all, and since the round-robin
      pointer can only ever point to real existing entries we don't need
      to perform any locking on the changing of the round-robin pointer
      itself.  We only need to reset the round-robin pointer to NULL when
      the entry it is pointing to is removed.
      
      The idea is from Thomas Graf and it is very similar to how this
      was implemented before the advanced router selection code when in.
      Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
      f11e6659
  7. 11 Feb, 2007 1 commit
  8. 13 Dec, 2006 1 commit
  9. 02 Dec, 2006 1 commit
  10. 22 Sep, 2006 7 commits
  11. 21 Jun, 2005 1 commit
  12. 16 Apr, 2005 1 commit
    • Linus Torvalds's avatar
      Linux-2.6.12-rc2 · 1da177e4
      Linus Torvalds authored
      Initial git repository build. I'm not bothering with the full history,
      even though we have it. We can create a separate "historical" git
      archive of that later if we want to, and in the meantime it's about
      3.2GB when imported into git - space that would just make the early
      git days unnecessarily complicated, when we don't have a lot of good
      infrastructure for it.
      
      Let it rip!
      1da177e4